3x + ky = 8
X – 2ky = 5
are simultaneous equations where k is a constant.
b) Given that y = 1/2 determine the value of k.
Answer:
(a): x is 3 and ky is -1
(b): k is -2
Step-by-step explanation:
Let: 3x + ky = 8 be equation (a)
x - 2 ky = 5 be equation (b)
Then multiply equation (a) by 2:
→ 6x + 2ky = 16, let it be equation (c)
Then equation (c) + equation (b):
[tex] { \sf{(6 + 1)x + (2 - 2)ky = (16 + 5)}} \\ { \sf{7x = 21}} \\ { \sf{x = 3}}[/tex]
Then ky :
[tex]{ \sf{2ky = 3 - 5}} \\ { \sf{ky = - 1}}[/tex]
[tex]{ \bf{y = \frac{1}{2} }} \\ { \sf{ky = - 1}} \\ { \sf{k = - 2}}[/tex]
Simultaneous equations are used to represent a system of related equations.
The value of k when [tex]y = \frac 12[/tex] is -2
Given that:
[tex]3x + ky = 8[/tex]
[tex]x - 2ky = 5[/tex]
[tex]y = \frac 12[/tex]
Substitute [tex]y = \frac 12[/tex] in both equations
[tex]3x + ky = 8[/tex]
[tex]3x + k \times \frac 12 = 8[/tex]
[tex]3x + \frac k2 = 8[/tex]
[tex]x - 2ky = 5[/tex]
[tex]x - 2k \times \frac 12 = 5[/tex]
[tex]x - k = 5[/tex]
Make x the subject in [tex]x - k = 5[/tex]
[tex]x = 5 + k[/tex]
Substitute [tex]x = 5 + k[/tex] in [tex]3x + \frac k2 = 8[/tex]
[tex]3(5 + k) + \frac k2 = 8[/tex]
Open bracket
[tex]15 + 3k + \frac k2 = 8[/tex]
Multiply through by 2
[tex]30 + 6k + k = 16[/tex]
[tex]30 + 7k = 16[/tex]
Collect like terms
[tex]7k = 16 - 30[/tex]
[tex]7k = - 14[/tex]
Divide both sides by 7
[tex]k = -2[/tex]
Hence, the value of constant k is -2.
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4. Find the height, x, of the building
Urgent please help
Answer:
D
Step-by-step explanation:
The function you need to use is the Tan(39).
Tan(x) = opposite / adjacent.
The opposite side does not make up the reference angle.
In this case, the opposite side = x
The adjacent side is not the hypotenuse and does make up the reference angle (which is not the right angle).
opposite = x
adjacent = 68
Tan(39) = x / 68 Multiply by 68
68*Tan(39) = x Divide by Tan(39)
Tan(39) = 0.9098
68*.9098 = x
x = 55.07
B
C
5
C
A
12
Find the length of “c” using
the Pythagorean Theorem.
Enter
Answer:
13
Step-by-step explanation:
We know that a^2+b^2 = c^2 where a and b are the legs and c is the hypotenuse
5^2 + 12^2 = c^2
25+144 = c^2
169 = c^2
Taking the square root of each side
sqrt(169) = sqrt(c^2)
13 =c
Evaluate the expression for x=-5,y=-7, and z=9
Answer:
Is 11
Step-by-step explanation:
x+(-y)+z —> -5 +(+7)+9 = -5+7+9 = 11
Why can't x^2+9 be factored? And is there a way to tell if a problem can be factored or not just by looking at it?
Answer:
There are no like terms
Step-by-step explanation:
×^2+9
=ײ+9
Cuantos años hay que tener un capital de 8500 euros a un redito de 3,75% para que produzca un interes de 2868,75 euros?
Respuesta:
9 años
Explicación paso a paso:
Dado :
Capital = Principal, P = 8500 €
Rendimiento, tasa, r = 3,75%
Intereses, i = 2868,75 €
Para obtener el plazo, número de años que se necesitarán para devengar un interés de 2868,75 € sobre un capital de 8500 € al tipo del 3,75%;
Interés = principal * tasa * tiempo
2868,75 € = 8500 € * 0,0375 * t
2868,75 € = 318,75 billones €
t = 2868,75 € / 318,75 €
t = 9
Por lo tanto, tomará un período de 9 años.
Daphne borrows $2500 from a financial institution that charges 6% annual interest, compounded monthly, for 2 years. The amount that Daphne will need to pay back at the end of the term is
please help me with these
Answer:
x= -1
y= 2.5
Step-by-step explanation:
15x+6y=0
4x-6y=-19
19x = -19
x=-1
-15+6y = 0
6y=15
y=2.50
Answer:
19x = -38
x = -2
(-2,5)
Step-by-step explanation:
3(5x + 2y = 0)
2(2x - 3y = -19)
First step is to simplify the equations by using the distributive property.
3(5x + 2y = 0)
distribute the 3 by multiplying 3 by everything inside of the parenthesis
3 * 5x = 15x
3 * 2y = 6y
3 * 0 = 0
first equation simplified: 15x + 6y = 0
2(2x - 3y = -19)
distribute the 2 by multiplying 2 by everything inside of the parenthesis
2*2x = 4x
2 * -3y = -6y
2 * -19 = -38
second equation simplified: 4x - 6y = -38
We acquire the two equations
15x + 6y = 0
4x - 6y = -38
Notice how there are two 6ys, one is negative and the other is positive. When this happens we can add the two equations together and solve for x. We can do this because the two 6ys will cancel out and we will be left with one variable. when there is only 1 variable you can solve it.
So add the two equations
+ 15x + 6y = 0
4x - 6y = -38
--------------------
19x = -38
now solve for x
divide both sides by 19
19x/19 = -38/19
x = -2
Now we need to find the value of y.
To do so simply plug in the value of x into one of the equations and solve for y
4x - 6y = -38
x = -2
4(-2) - 6y = -38
multiply 4 and -2
-8 - 6y = -38
add 8 to both sides
-6y = -30
divide both sides by -6
y = 5
The solution to the system is (-2,5)
What percent of 500 is 125
Answer:
25%
Step-by-step explanation:
125 of 500 can be written as: 125 /500
To find a percentage, we need to find an equivalent fraction with the denominator 100. Multiply both numerator & denominator by 100.
125 /500 × 100 /100
= ( 125 × 100/ 500 ) × 1 /100 = 25 /100
Answer:
25%
Step-by-step explanation:
Of means multiply and is means equals
P *500 = 125
Divide each side by 500
P = 125/500
P = .25
Change to percent form
P = 25%
Mahmoud earns $450 per week plus a 20% commission as a car salesman. He wants his
hourly salary to be at least $35.
The inequality that relates the number of hours to the weekly sales is:
[tex]450 + 0.20x \ge 35y[/tex]
The complete question implies that we define an inequality that represents the relationship between the number of hours worked in a week and the weekly sales
We make use of the following representation:
[tex]x \to[/tex] weekly sales from cars.
[tex]y \to[/tex] hours worked in a week
His weekly salary is then calculated as:
Salary (S) = Earnings per week + Commission * Sales from car
So, we have:
[tex]S = 450 + 20\% * x[/tex]
Express percentage as decimal
[tex]S = 450 + 0.20* x[/tex]
[tex]S = 450 + 0.20x[/tex]
Assume he works for y hours in a week.
His hourly rate is:
[tex]Hourly = \frac{S}{y}[/tex] --- i.e. weekly salary divided by number of hours
[tex]Hourly = \frac{450 + 0.20x}{y}[/tex]
For this rate to be at least [tex]\$35[/tex], the following condition must be true
[tex]Hourly \ge 35[/tex] --- i.e. is hourly rate must be greater than or equal 35
So, we have:
[tex]\frac{450 + 0.20x}{y} \ge 35[/tex]
Multiply both sides by y
[tex]450 + 0.20x \ge 35y[/tex]
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Y = 2x - 4
(0, 4)
(3, -1)
(-1, -5)
(-4, 9)
Answer:
Y = 2x - 4
(2,-4)
gradient= 2
y-intersept = -4
Which is an Irrational Number?
A. 11.23453
B. -22
C. 2 2/3
D. 225 pi
what is the product of 7/9 and 1/4 in fraction form?
Answer:
Wdym? that is fraction form, but if you ment decimal form; it is .7777 repeating and .25
Step-by-step explanation:
Instructions: Find the angle measures given the figure is a rhombus.
Answer:
m <1 = 147
m <2 = 90
Step-by-step explanation:
In rhombus diagonals are perpendicular to each other so
m <2 = 90
m < 1 = 180- 33
= 147
Answered by Gauthmath
The required angle of the rhombus m∠1 = 57° and m∠2 = 90°.
Given that,
A figure of a rhombus is shown,
An angle of 33° is given,
m∠1 and m∠2 is to be determined.
The triangle is a geometric shape that includes 3 sides and sum of the interior angle should not greater than 180°.
The angle can be defined as the one line inclined over another line.
Here, the rhombus has been shown with an angle of 33° of the side with one of the diagonal.
Since the diagonal of the rhombus bisect each other at an angle of 90 so the angle m∠2 = 90 and the sum of the interior angle of a triangle is 180. So,
m∠1 + 33 + 90 = 180
m∠1 = 180 - 123
m∠1 = 57
Thus, the required angle of the rhombus m∠1 = 57° and m∠2 = 90°.
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#SPJ5
Identify the perimeter and area of an equilateral triangle with height 12 cm. Give your answer in simplest radical form.
Answer:
perimeter is 36 cm
Step-by-step explanation:
how does translation affect the properties of a two-dimensional figure? please i need help
Answer:
It affects the location of the shape and how the shape looks. It doesn't affect the area or perimeter though.
Step-by-step explanation:
will give brainlest pls help me with all three questions
Answer:
Hello,
Step-by-step explanation:
3)
[tex]x^2-4x+3=0\\x^2-3x-x+3=0\\x(x-3)-(x-3)=0\\(x-3)(x-1)=0\\\\x-intercepts\ are\ x=3\ or\ x=1[/tex]
4)
[tex]-x^2-8x+12=0\\x^2+8x-12=0\\(x^2+2*4x+16)-16-12=0\\\\(x+4)^2-28=0\\\\\\(x+4-2\sqrt{7} )((x+4+2\sqrt{7} )=0\\\\x-intercepts\ are \ x=-4+2\sqrt{7}\ and\ x=-4-2\sqrt{7}\\\\[/tex]
5)
[tex]f(x)=-3(x-7)(x+4)\\=-3(x^2-3x-28)\\\\=-3(x^2-2*\dfrac{3}{2} *x+\dfrac{9}{4} )+\dfrac{27}{4} +84\\\\=-3(x-\dfrac{3}{2})^2+\dfrac{363}{4} \\\\\\Vertex\ is\ (\dfrac{3}{2},\dfrac{363}{4})[/tex]
Help please !!!!!!!!!
Answer: (a): Good course, (b): Bad course
Step-by-step explanation:
Firstly, because the standard deviation of the good course results is lower, there is less variation so he performs more consistently there.
Secondly, the trick with the second question is that while the mean of the bad course is slightly less, the standard deviation is quite a lot higher than that of the good course, so it's more likely that the highest single test score belongs to the bad course.
Does the verbal description c minus 12
Answer:
Yes.
Step-by-step explanation:
Minus and difference mean the same thing. To find the difference, you subtract or minus, so they are the same thing.
X^4+x^3-6x^2-14x-12=0 Make a list of possible rational roots. Test the possible roots until you find one that produces a remainder of 0 Write the resulting cubic function. Use synthetic division to find a second root that will reduce the cubic expression to a quadratic expression
Step-by-step explanation:
The Rational Roots Test states that for a polynomial with integer coefficients, the factors of the constant / the factors of the leading coefficient are the possible rational roots.
Here, the constant (the value without an x attached to it) is -12 and the leading coefficient (the value that the x to the highest degree is multiplied by) is 1 as x⁴ is multiplied by 1. The factors of -12 are
±(1, 2, 3, 4, 6, 12), so the possible rational roots are ±(1, 2, 3, 4, 6, 12)/1 (as 1 is the only factor of 1).
Trying out a few roots until we get one that works using synthetic division, we can try
x+1 (the root is x=-1)
-1 | 1 1 -6 -14 -12
| -1 0 6 8
__________________________
1 0 -6 -8 -4
the remainder is -4, so this does not work
x+2 (the root is x=-2)
-2 | 1 1 -6 -14 -12
| -2 2 8 12
__________________________
1 -1 -4 -6 0
Therefore, x=-2 is a root and x+2 is a factor of the polynomial. The quotient of the polynomial and x+2 is
-6 + (-4)x + (-1)* x² + 1 * x³ = x³-x²-4x-6
Using the rational roots theorem, the possible roots of x³-x²-4x-6 are
±(1,2,3,6)
Starting with
x-1 (root is x=1), we have
1 | 1 -1 -4 -6
| 1 0 -4
_____________________
1 0 -4 -10
there is a remainder, so this is not a root
next, x-2 (root is x=2)
2 | 1 -1 -4 -6
| 2 2 -4
_____________________
1 1 -2 -10
there is a remainder, so this is not a root
next, x-3 (root is x=3)
3| 1 -1 -4 -6
| 3 6 6
_____________________
1 2 2 0
x-3 is a factor and 3 is a root. the quotient of (x³-x²-4x-6)/(x-3) is x²+2x+2
SOMEONE HELP ME PLEASE
Answer:
so thats 2/6 or 1/3
Step-by-step explanation:
A die has 6 sides your odds of getting 2 or lesser are 1/3 or 33%
47. The legs of a triangle measure 7 mm and 24 mm. What length hypotenuse makes the triangle a right triangle?
A. 23 cm
B. 25 cm
C. 161 cm
D. 289 cm
Answer:
B
Step-by-step explanation:
according to pythagorean
[tex]7^{2} + 24^{2} =x^{2}[/tex] (x>0)
=> [tex]x^{2} =625[/tex]
=>[tex]x=\sqrt{625}[/tex] = 25
HELP ANSWER ASAP. what is the radius of a circle in which a 30 arc is 2pi inches long?
Answer:
I believe it's 12 in.
Step-by-step explanation:
hope this helps you!
How to find the absolute value of |2b+4| with b=-8
Step-by-step explanation:
the absolute value simply removes a negative sign, if there is one. if there is no negative sign, it leaves the argument untouched.
so, we need to calculate the argument first :
2b + 4 = 2×-8 + 4 = -16 + 4 = -12
|-12| = 12
that's it.
If a sine curve has a vertical shift down 19 units with an amplitude of 21, what will the minimum and maximum values be? (i.e. how high and low will the graph go?)
Min Value:
Max Value:
Given:
Amplitude = 21
Vertical shift = 19 units down
To find:
The maximum and the minimum value.
Solution:
The general form of sine function is:
[tex]y=A\sin (Bx+C)+D[/tex]
Where, |A| is amplitude, [tex]\dfrac{2\pi}{B}[/tex] is period, [tex]-\dfrac{C}{B}[/tex] is phase shift and D is the vertical shift.
Here,
[tex]Maximum=D+A[/tex]
[tex]Minimum=D-A[/tex]
We have,
Amplitude: [tex]A = 21[/tex]
Vertical shift: [tex]D=-19[/tex]
Negative sign means shifts downwards.
Now,
[tex]Maximum=D+A[/tex]
[tex]Maximum=-19+21[/tex]
[tex]Maximum=2[/tex]
And,
[tex]Minimum=D-A[/tex]
[tex]Minimum=-19-21[/tex]
[tex]Minimum=-40[/tex]
Therefore, the minimum value is -40 and the maximum value is 2.
Someone help asappppp
Answer:
all have "bases" less than one which is a decay...
only "C" is greater than 1 (1.01)
"C" is the answer
Step-by-step explanation:
1. (01.03 LC)
Lillie is saving up for a trip she is taking with friends during her break from school. If Lillie's current monthly net pay is $490.00 and her monthly expenses are $387.10,
what percent of her net pay is left for savings? (2 points)
21%
27%
45%
Taking into account the definition of percentage, the correct option is: 21 percent of her net pay is left for savings.
First of all, the percentage represents a given quantity that establishes relationships between two quantities, using the number 100 as a reference.
That is, the percentage indicates what part of a total represents a quantity.
To obtain the percentage, the division must be made between the portion of the total and the total amount that belongs to the set, whose result is multiplied by 100.
In this case, if Lillie's current monthly net pay and her monthly expenses are $ 387.10, and I assume that the rest of the money is saved by Lillie, then the amount of money saved is $ 490 - $ 387.10 = $ 102.9.
Then:
portion of the total= amount of money saved= $102.9total amount= Lillie's current monthly net pay= $490So, the percentage is calculated as:
percentage= (102.9÷490) ×100
percentage= 0.21×100
percentage= 21%
The correct option is: 21 percent of her net pay is left for savings.
Learn more about percentage with this examples:
brainly.com/question/19295956?referrer=searchResultsbrainly.com/question/1301322?referrer=searchResultsThe exchange rate between dollars ($) and pounds (£) is $1 = £0.65 . The exchange rate between euros (€) and pounds is €1 = £0.74 . Khan changes €520 into pounds. He spends £260 and then changes the rest into dollars. Work out how many dollars he receives
Answer:
€520=£442.83
=£442.83-£260
=£182.83 into dollars=$251.52
Therefore he receives $251.52
Please hhhhhhhhhhhhhhhhheeeeeeeeellllppppppppp Simplify
Answer:
Does the answer help you?
Answer:
6/(x + 4)(x - 2)
Step-by-step explanation:
(12x - 96)/(x² - 4x - 32) ÷ (6x² - 6x - 12)/(3x + 3)
12x - 96 = 12(x - 8)
x² - 4x - 32 = (x - 8)(x + 4)
(12x - 96)/(x² - 4x - 32) = 12/(x + 4)
6x² - 6x - 12 = (3x + 3)(2x - 4)
(6x² - 6x - 12)/(3x + 3) = 2x - 4 = 2(x - 2)
(12x - 96)/(x² - 4x - 32) ÷ (6x² - 6x - 12)/(3x + 3) = 12/(x + 4) ÷ 2(x - 2) = 12/(x + 4) × 1/2(x - 2) = 6/(x+4)(x-2)
Utilize graphing to find the solution to
the following system of equations.
4x + 3y = 25 AND y = -5x + 1
([?], [])
Answer:
you guess any value of x and then you substitute any three values for example for the first equation you can guess the value of x to be 1 or 2 or 3