find the value of discriminant of the equation X square + 10 x - 7 =02
​

Answer:

The speed of the normal train is 60 kilometers per hour.

Step-by-step explanation:

Let suppose that both trains move at constant speed and cover the same distance. Then, we have the following identity:

[tex]v_{1}\cdot t_{1} = v_{2}\cdot t_{2}[/tex] (1)

Where:

[tex]v_{1}, v_{2}[/tex] - Average speeds of the express train and the normal train, in kilometers per hour.

[tex]t_{1}, t_{2}[/tex] - Travel times of the express train and the normal train, in hours.

In addition, there is the following relationship between average speeds:

[tex]v_{1} = v_{2} + 90[/tex] (2)

By (2) in (1), we have the following expression for the average speed of the normal train:

[tex](v_{2} + 90) \cdot t_{1} = v_{2}\cdot t_{2}[/tex]

[tex]90\cdot t_{1} = v_{2} \cdot (t_{2} - t_{1})[/tex]

[tex]v_{2} = \frac{90\cdot t_{1}}{t_{2}-t_{1}}[/tex]

If we know that [tex]t_{1} = 4\,h[/tex] and [tex]t_{2} = 10\,h[/tex], then the average speed of the normal train is:

[tex]v_{2} = 90\cdot \left(\frac{4\,h}{10\,h - 4\,h} \right)[/tex]

[tex]v_{2} = 60\,\frac{km}{h}[/tex]

The speed of the normal train is 60 kilometers per hour.

Answer:

8. x = 16

9. x = 10

14.

m ∠RSU = 130°

m ∠UST = 50°

15.

m ∠RSU = 124°

m ∠UST = 56°

Step-by-step explanation:

8.

Given ∠DEF is bisected by EG. That is , ∠DEG = ∠GEF

That is , (x + 15)° = 31°

                x = 31 - 15 =  16

9.

Given ∠DEF is bisected by EG. That is , ∠DEG = ∠GEF

That is ,

           (6x - 4)° = 56°

            6x = 56 + 4

               6x = 60

                 x = 10

14.

13x + 5x = 180°                       [straight line angles ]

18x = 180

x = 10

m ∠RSU = 130°

m ∠UST = 50°

15.

4x + 12 + 2x = 180°                       [ straight line angles]

6x = 180 - 12

6x = 168

x = 28

m ∠RSU = 4(28) + 12 = 112 + 12 = 124°

m ∠UST = 2(28) = 56°

Answer:

14. 13x+5x

=18x

180(angles on a st. line)= 18x

180/18

=10

RSU=13*10=130

UST=5*10=50

Answer:

Tn = 75+25n

Step-by-step explanation:

The balance are in arithmetic progression

$100, $125, $150...

The formula for calculating the nth term of the sequence is expressed as;

Tn = a+(n-1)d

a =100

d = 125 - 100 = 150 - 125

d = 25

n is the number of terms

Substitute

Tn = 100+(n-1)*25

Tn = 100 + 25n-25

Tn = 75+25n

Hence the nth term of the sequence is Tn = 75+25n

Answer:

40 %

Step-by-step explanation:

no of members in youth club = 150

no of girls = 60

girls percentage = ?

girls percentage = no of girls / total members * 100%

= 60 / 150 *100%

=6000 / 150

=40 %

Answer:

c or b

tep-by-step explanation:

Answer:

Step-by-step explanation:

When you ask "which of the following"

you must include the choices

Answer:D - mean>median

Step-by-step explanation:

There are no repeating variables to have a mode so median and mean are the only options. The mean of this data set is 7.4 and the median is 6. Therefore mean greater than median

Answer:

A) x + 5y = 20

B) x + 3y = 14

Multiplying A) by -1

A) -x -5y = -20 then adding B)

B) x + 3y = 14

-2y = -6

y = 3

x = 5

Step-by-step explanation:

Answer:

option A

Step-by-step explanation:

   [tex]y - 9 = \frac{2}{3} (x + 7)\\\\ y - 9= \frac{2}{3} x + \frac{14}{3}\\\\ y = \frac{2}{3} x + \frac{14}{3} + 9\\\\y = \frac{2}{3}x + \frac{14 +27}{3}\\\\y = \frac{2}{3}x + \frac{41}{3}\\\\[/tex]

Therefore, slope of the given line is

                                                    [tex]m_ 1 = \ \frac{2}{3}[/tex]

Find the slope of the new line

The product of slope of  lines perpendicular to each other = - 1

That is ,

            [tex]m_ 1 \times m_2 = - 1\\\\\frac{2}{3} \times m_ 2 = - 1\\\\m_ 2 = - \frac{3}{2}[/tex]

Find the equation of the line.

[tex]Let \the \ given \ points \ be \ ( x_ 2 , y _ 2 ) = ( 2 , 3 ) \\\\(y- y_2) = m_2 (x - x_ 2)\\\\( y - 3 ) = - \frac{3}{2}(x - 2)\\\\y = -\frac{3}{2}x + \frac{3 \times 2}{2} + 3\\\\y = - \frac{3}{2} x +3+3\\\\y = - \frac{3}{2} x +6\\\\[/tex]

Answer:

≈ 35.1 ft

Step-by-step explanation:

The model is a right triangle with ladder being the hypotenuse and the angle between the ground and the ladder is 70°

Using the cosine ratio, with l being the length of the ladder.

cos70° = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{12}{l}[/tex] ( multiply both sides by l )

l × cos70° = 12 ( divide both sides by cos70° )

l = [tex]\frac{12}{cos70}[/tex] ≈ 35.1 ( to the nearest tenth )

The ladder is approx 35.1 ft long

Answer:

Step-by-step explanation:

a = 7 ;  b = 1 ;  c = -5

D = b² - 4ac

  = 1 - 4*7*(-5)

  = 1 + 140

  = 141

x =( - b ± √D ) / 2a

 = (-1 ± √141)/2*7

 = (-1±√141) / 14

[tex]a = \frac{-1+\sqrt{141} }{14}= \frac{-1+11.87}{14}= \frac{10.87}{14}=0.78\\\\b = \frac{-1-\sqrt{141}}{14}= \frac{-1-11.87}{14}= \frac{-12.87}{14}=3.59\\\\\\[/tex]

(a -4 )(b -4) = (0.78 - 4)(-3.59-4) = (-3.22)(-7.59)

= 24.4398

Answer:

c =2

Step-by-step explanation:

4.5c/4.5=9/4.5

c =2

Answer:

(-1,3)

Step-by-step explanation:

Solve for x in the first equation

3x = 6 - 3y

9x - 5y= -24

Replace all occurrences of x with 2 - y in each equation

9(2 - y) - 5y = -24

x = 2 - y

Simplify the left side

18 - 4y = -24

x = 2 - y

Solve for y in the first equation

-14y = -42

x = 2 - y

y=3

x = 2- y

Replace all occurrences of y with 3 in each equation

x=-1

y=3

(-1,3)

Hope this helps!

Please give brainliest :)

If you need more help with these types of equations reach out to me!

Simplifying

3x + 6 = 9x + -24

Reorder the terms:

6 + 3x = 9x + -24

Reorder the terms:

6 + 3x = -24 + 9x

Solving

6 + 3x = -24 + 9x

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-9x' to each side of the equation.

6 + 3x + -9x = -24 + 9x + -9x

Combine like terms: 3x + -9x = -6x

6 + -6x = -24 + 9x + -9x

Combine like terms: 9x + -9x = 0

6 + -6x = -24 + 0

6 + -6x = -24

Add '-6' to each side of the equation.

6 + -6 + -6x = -24 + -6

Combine like terms: 6 + -6 = 0

0 + -6x = -24 + -6

-6x = -24 + -6

Combine like terms: -24 + -6 = -30

-6x = -30

Divide each side by '-6'.

x = 5

Simplifying

x = 5

Step-by-step explanation:

the asymptotes of f(x) :

(4x-π) = π/2

4x = 3π/2 => x = 3π/8

(4x-π) = 3π/2

4x=5π/2 => x = 5π/8

the answer is

D. X= 3pi/8, x=5pi/8

Answer:

[tex]2x^{2} +bx-3=0[/tex]

Step-by-step explanation:

General form. A quadratic function [tex]f(x)[/tex] is of the form [tex](ax^2+bx+c)[/tex] where [tex]a,b,c[/tex] ∈ R or C and [tex]a[/tex] ≠ [tex]0[/tex].

We obtain an equation when [tex]f(x)=0[/tex]

⇒ [tex]ax^{2} +bx+c=0[/tex] is an quadratic equation.

Solution.

Given, [tex]a=2,c=-3[/tex], but b is not given

Thus the quadratic function with leading coefficient [tex]a=2[/tex] and constant term [tex]c=-3[/tex] is given by

[tex]f(x)=2x^{2} +bx-3[/tex]

∴ the required quadratic equation is

[tex]2x^{2} +bx-3=0[/tex]

Answer:

m=-2

Step-by-step explanation:

Answer:

t-6=7 .................

Answer:

t - 6 = 7

Step-by-step explanation:

Answer:

A weak positive correlation

Step-by-step explanation:

The table of values of the women's age to shoe size is presented as follows;

Women's Age and Shoe Size

[tex]\begin{array}{ccc} Age&&Shoe \, size\\18&&7\\30&&10\\52&&6\\64&&9\end{array}[/tex]

We get;

The correlation coefficient, r, is given as follows;

[tex]r = \dfrac{\sum \left(x_i - \overline x \right ) \cdot \left(y_i - \overline y \right )}{\sqrt{ \sum \left(x_i - \overline x \right )^2 \cdot \sum \left(y_i - \overline y \right )^2}}[/tex]

From MS Excel, we have;

[tex]\sum \left(x_i - \overline x \right ) \cdot \left(y_i - \overline y \right )[/tex] = 2

[tex]\sqrt{ \sum \left(x_i - \overline x \right )^2 \cdot \sum \left(y_i - \overline y \right )^2}[/tex] = √13,000 = 10·√130

∴ r = 2/(10·√130) ≈ 0.01754

Therefore, given that the calculated correlation coefficient, r is positive and less than 0.2 (weak), we have

The correlation is a weak and positive.

Answer:

9

Step-by-step explanation:

5×9=45

Hope this helps! :)

Answer:

9

Step-by-step explanation:

5x9=45

45 ÷ 5 = 9

45 ÷ 9 = 5

Answer:

9 over 5

Step-by-step explanation:

Answer:

Step-by-step explanation:

x^2 + 12 - 45 = 0

solving by middle term break method

x^2 + (15 - 3) - 45 = 0

x^2 + 15x - 3x - 45 = 0

x(x + 15) - 3(x + 15) = 0

(x + 15)(x - 3) = 0

either x + 15 = 0            OR, x - 3 = 0

x + 15 = 0

x = 0 -15

x = -12

x - 3 = 0

x = 0 + 3

x = 3

therefore x = -12,3

i have done solution for the given question in two different methods.

the solution done in note copy is by using quadratic formula.

Given:

[tex]\sin \theta <0[/tex]

[tex]\tan \theta <0[/tex]

To find:

The quadrant in which [tex]\theta[/tex] lie.

Solution:

Quadrant concept:

In Quadrant I, all trigonometric ratios are positive.

In Quadrant II, only [tex]\sin\theta[/tex] and [tex]\csc\theta[/tex] are positive.

In Quadrant III, only [tex]\tan\theta[/tex] and [tex]\cot\theta[/tex] are positive.

In Quadrant IV, only [tex]\cos\theta[/tex] and [tex]\sec\theta[/tex] are positive.

We have,

[tex]\sin \theta <0[/tex]

[tex]\tan \theta <0[/tex]

Here, [tex]\sin\theta[/tex] is negative and [tex]\tan\theta[/tex] is also negative. It is possible, if [tex]\theta [/tex] lies in the Quadrant IV.

Therefore, the correct option is D.

Answer:

0.4

Step-by-step explanation:

If we count up all of the colored squares, we will get 28. And if we count the non-colored squares we will get 72.

Now, we take 28 and we divide it by 72. This will get us 0.3888888. That number rounded up is 0.4.

Hope this helps and if it does, don't be afraid to give my answer a "Thanks" and maybe a Brainliest if it's correct?  

Answer:

Step-by-step explanation:

Clara gave (1/2) of formal dresses to her sister. After giving, she has 1/2

of formal dresses (1- 1/2 = 1/2).

Number of formal dresses that Clara has = [tex]\frac{1}{2}*d=\frac{1}{2}d[/tex]

Clara bought 4 more dresses

[tex]\frac{1}{2}d + 4 = 12[/tex]

Answer: 52

Step-by-step explanation:

81 + 47 is 128.

180 - 128 =52 degrees.

:)

Answer:

a= 16

b= 2

Step-by-step explanation:

edge 2021

Answer:

a=16 and b=2

Step-by-step explanation:

next one is B.

Step-by-step explanation:

Hey there!

Given;

Distance (d) = 450 km = 450*1000 = 450000 m

Time(t) = 5 hours = 5*60*60 = 18000s

Now;

Speed (s) = Distance (d) /Time(t)

Or, s = 450000/18000

Or, s = 25m/s.

Therefore, the speed is 25m/s.

Hope it helps!

Answer:

The car has a velocity of 25 m/s.

Step-by-step explanation:

There are two ways to solve this problem.

First way :

450km = 450.000m

5h = 5x 3.600s =18.000s

v = s/t = 450.000 / 18.000 = 25m/s

Second way :

Velocity = speed/time = 450 / 5 = 90 km/h

90/3.6 = 25 m/s

Either way, the car has a velocity of 25 m/s.

Draw an equilateral triangle with side lengths 5 inches each. Each interior angle is 60 degrees (this is true of any equilateral triangle).

Now draw an equilateral triangle of 10 inches each. The angles will be the same as before. We can see that the triangles are not congruent. Congruent triangles must have the same side lengths, but clearly the second one is larger than the first.

This is an example of why knowing solely the congruency of the angles is not enough to prove the triangles congruent or not. We would need to know something about the sides (whether they are congruent or not) to be able to determine overall triangle congruency.

Answer:

Because even though the angles may be the same, the lengths can be different. In an isosceles triangles, this may be the case.

Step-by-step explanation:

Answer:

20

Step-by-step explanation:

The numbers whose product are to be obtained :

(–24.98)(–1.29)

To use front end approximation, numbers are rounded to the greatest place value :

For :

(-24.98) is rounded to - 20 (4 is rounded here to 0)

(-1.29) is rounder to - 1 (2 is rounded to 0)

Then, the product of the two numbers will be :

-20 * - 1 = 20

Answer:

B

Step-by-step explanation:

So if B is the midpoint of AC, AB must be 1/2 of AC.

If D is the midpoint of AB, it must be 1/2 of 1/2 of AC, which is 1/4 of AC.

So AC= 4 DB