evaluate the expression when x=7 and y= -2 -x+8y​

Answer:

Substitute in the values of both given coordinates & form 2 equations:

[tex]\left \{ {{A(2)+B(-1)=1} \atop {A(-3)+B(-2)=1}} \right. \\\\=\left \{ {{2A-B=1} \atop {-3A-2B=1}} \right.[/tex]

Find the value of B from the equation 2A - B = 1:

[tex]2A-B=1\\-B=1-2A\\B=2A-1[/tex]

Substitute in the B-value to the other equation:

[tex]-3A-2B=1\\-3A-2(2A-1)=1\\-3A-4A+2=1\\-7A=1-2\\-7A=-1\\A=\frac{-1}{-7} =\frac{1}{7}[/tex]

Find the B-value using the equation from before:

[tex]B=2A-1=2(\frac{1}{7})-1=\frac{2}{7} -\frac{7}{7} =-\frac{5}{7}[/tex]  

Therefore the equation Ax + By = 1 would equal:

[tex]\frac{1}{7} x-\frac{5}{7} y=1[/tex]

9514 1404 393

Answer:

  the correct choice is marked

Step-by-step explanation:

The end behavior matches that of an odd-degree polynomial. The only function shown that has that behavior is the one marked:

  [tex]f(x)=\dfrac{x^2-36}{x-6}=\dfrac{(x+6)(x-6)}{(x-6)}=x+6\qquad x\ne6[/tex]

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Additional comment

The other functions have horizontal (not slant) asymptotes, so do not have the described end behavior.

  B: y=0

  C, D: y=1

Answer:

(c) (f-g ) (x) = 6x*3 -2x*2 +4x -8

Answer:

Step-by-step explanation:

This is not possible over the real numbers system. You cannot take the square root of a negative number without ending up with imaginary solutions.

[tex]x^2=-25[/tex] and

[tex]x=\sqrt{-25}[/tex] In the world of imaginary numbers, the 2 solutions would be

x = 5i and x = -5i

Answer:

It should be x=5i-5i

Step-by-step explanation:

Answer:

Hence the required probability is, 3/4

Step-by-step explanation:  

At the shelter, he likes :  

a male coolie, a female coolie, a male boxer, a female boxer, a male beagle, a female beagle, a male Labrador, and a female Labrador.  

Let, A denote the event of selecting a male coolie and B denote the event of selecting a male Labrador.  

P(A) = 1/8 = P(B)  

Here the probability of selecting a puppy except A & B is,  

P(AUB)c = 1 - P(AUB) = 1 - { P(A) + P(B) } = 1 - 1/8 - 1/8 = 3/4

Hey there!

A right pyramid with a square base just means that it isn't slanted all funny. If you create a triangle with a point on one of the edges of the base, the center of the base, and the top of the pyramid, it would be a right triangle.

To find the volume of a right pyramid, you just take the base area, multiply it by the height, and then divide by three.

However, we are looking for the height. We have been given, so we will just go backwards.

252×3=756 (multiply instead of divide)

6×6=36 (base is a square, so you just square 6. This is our base area)

756/36=21

So, the vertical height of the pyramid is 21 cubic centimeters.

Have a wonderful day! :D

Answer:

just show the questions i will help

Step-by-step explanation:

Answer:

0.25meters

As 100cm=1metre

so, 25cm=25/100meter

=0.25metre

Step-by-step explanation:

If you like my answer than please mark me brainliest

The answer is 0.25 meters

9.03 divided by 899.8 is closest to a.0.01

Answer: a) 0.01

Step-by-step explanation:

Answer:

1.23

Step-by-step explanation:

Answer:

(x - 3) inches

Step-by-step explanation:

the ratio of -15 (of the area term) and +5 (of the length term) suggests a term for the width ending in -3. and we need an x in there to get x² for the area.

so, immediate assumption is (x-3) for the width.

let's check

(x+5)(x-3) = x² + 5x - 3x - 15 = x² + 2x - 15

correct.

9514 1404 393

Answer:

  a) 2.038 seconds

  b) 5.918 meters

  c) 1.076 seconds

Step-by-step explanation:

For the purpose of answering these questions, it is convenient to put the given equation into vertex form.

  h = -4.9t² +9.2t +1.6

  = -4.9(t² -(9.2/4.9)t) +1.6

  = -4.9(t² -(9.2/4.9)t +(4.6/4.9)²) +1.6 +4.9(4.6/4.9)²

  = -4.9(t -46/49)² +290/49

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a) To find h = 0, we solve ...

  0 = -4.9(t -46/49)² +290/49

  290/240.1 = (t -46/49)² . . . . subtract 290/49 and divide by -4.9

  √(2900/2401) +46/49 = t ≈ 2.0378 . . . . seconds

The ball takes about 2.038 seconds to fall to the ground.

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b) The maximum height is the h value at the vertex of the function. It is the value of h when the squared term is zero:

  290/49 m ≈ 5.918 m

The maximum height of the ball is about 5.918 m.

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c) We want to find t for h ≥ 4.5.

  h ≥ 4.5

  -4.9(t -46/49)² +290/49 ≥ 4.5

Subtracting 290/49 and dividing by -4.9, we have ...

  (t -46/49)² ≥ 695/2401

Taking the square root, and adding 46/49, we find the time interval to be ...

  -√(695/2401) +46/49 ≤ t ≤ √(695/2401) +46/49

The difference between the interval end points is the time above 4.5 meters. That difference is ...

  2√(695/2401) ≈ 1.076 . . . . seconds

The ball is at or above 4.5 meters for about 1.076 seconds.

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I like a graphing calculator for its ability to answer these questions quickly and easily. The essentials for answering this question involve typing a couple of equations and highlighting a few points on the graph.

_____

Additional comment

I have a preference for "exact" answers where possible, so have used fractions, rather than their rounded decimal equivalents. The calculator I use deals with these fairly nicely. Unfortunately, the mess of numbers can tend to obscure the working.

"Vertex form" for a quadratic is ...

  y = a(x -h)² +k . . . .  where the vertex is (h, k) and 'a' is a vertical scale factor.

In the above, we have 'a' = -4.9, and (h, k) = (46/49, 290/49) ≈ (0.939, 5.918)

Answer:

B. The largest exponent value of the a terms is equal to the value of the exponent on the binomial. The exponent values then decrease from left to right.

Step-by-step explanation:

The exponent values of the a terms increase from one side of the binomial to the other. The value of the largest exponent is equal to part of the binomial expression.

Answer:

x = 20.8

y = 22.3

Step-by-step explanation:

tan(21) = 8/x

or, x = 8/tan(21)

or, x = 20.8 (rounded to the nearest tenth)

sin(21) = 8/y

or, y = 8/sin(21)

or, y = 22.3 (rounded to the nearest tenth)

Answered by GAUTHMATH

Answer:

1250000cm

Step-by-step explanation:

1:500000

1x2.5 : 500000x2.5

2.5:1250000

Answer:

13 cup i hope this help

Step-by-step explanation:

The 8 will end up in the "ones place".

When 'a' is divided by 'b', then the result we get from the division is the part of 'a' that each one of 'b' items will get. Division can be interpreted as equally dividing the number that is being divided into total x parts, where x is the number of parts the given number is divided.

We need to find the 8 will end up in which place

A negative divided by a negative is positive, then;

2380/ 10 = 238

Therefore, The 8 will end up in the _ ones_ place.

Learn more about division here:

brainly.com/question/26411682

#SPJ2

Answer:

If you multiply a decimal by 10, the decimal point will move one place to the right. If you divide a decimal by 10, the decimal point will move one place to the left.

Step-by-step explanation:

Multiplying a decimal by 10 increases the value of each digit by 10. Multiplying a decimal by a power of 10 increases the value of each digit by a number of times that is equivalent to that power of 10. When a digit's value is changed, that digit is moved to the appropriate place.

It looks like you want to find

[tex]\displaystyle \int t^{11} e^{-t^6}\,\mathrm dt[/tex]

Substitute u = -t ⁶ and du = -6t ⁵ dt. Then

[tex]\displaystyle \int t^{11} e^{-t^6}\,\mathrm dt = \frac16 \int (-6t^5) \times (-t^6) e^{-t^6}\,\mathrm dt = \frac16 \int ue^u \,\mathrm du[/tex]

Integrate by parts, taking

f = u   ==>   df = du

dg = eᵘ du   ==>   g = eᵘ

Then

[tex]\displaystyle \frac16 \int ue^u \,\mathrm du = \frac16\left(fg-\int g\,\mathrm df\right) \\\\ =\frac16 ue^u - \frac16\int e^u\,\mathrm du \\\\ =\frac16 ue^u - \frac16 e^u + C \\\\ =-\frac16 t^6 e^{-t^6} - \frac16 e^{-t^6} + C \\\\ =\boxed{-\frac16 e^{-t^6} \left(t^6+1\right) + C}[/tex]

Answer:

8. SU = 24

9. TU = 16√3

Step-by-step explanation:

Recall: SOH CAH TOA

8. Reference angle (θ) = 30°

Opposite = 8√3

Adjacent = SU

Apply TOA,

Tan θ = Opp/Adj

Substitute

Tan 30° = 8√3/SU

Tan 30° × SU = 8√3

SU = 8√3/Tan 30°

SU = 8√3/(1/√3) (tan 30° = 1/√3)

SU = 8√3*√3/1

SU = 8*3

SU = 24

9. Reference angle (θ) = 30°

Opposite = 8√3

Hypotenuse = TU

Apply SOH,

Sin θ = Opp/Hyp

Substitute

Sin 30° = 8√3/TU

Sin 30° × TU = 8√3

TU = 8√3/sin 30°

TU = 8√3/(½) (sin 30° = ½)

TU = 8√3 × 2/1

TU = 16√3

Step-by-step explanation:

A-B

=7x-6x/2 +10) - (-2x +6x-4)

=x/2+10- 4x+4

= x-8x /2 +14

=-7x/2+14

Answer:

1) D - 30 cm 2) 12 percents

Step-by-step explanation:

The first question was If two perpendicular sides of a right-angled triangle are 5 cm and 12 cm, its perimeter is: (A) 13 cm (B) 17 cm (C) 27 cm (D) 30 cm

two perpendicular sides are legs, find the hipotenuse of the triangle

It is equal to sqrt(5^2+12^2)= sqrt169=13

5+12+13=30 - D - the perimeter

The second question

7500 -100 percents

8400- x

7500/8400=100/x

75/84=100/x

(25/28)*x=100

(1/28)*x=4

x=4/(1/28)= 4*28= 112 percents

The profit is 12 percents

2) Option D is correct. If two perpendicular sides of a right-angled triangle are 5 cm and 12 cm, its perimeter will be 30cm.

3) None of the given options are correct. If an article is purchased for 7,500 and sold for 8,400, the profit percentage will be 12%

2) A right-angled triangle is a triangle with three sides and one of its angles is 90degrees. Find the image of a right-angled triangle attached below.

The triangle consists of 3 sides which are:

Before we can get the perimeter of the right triangle, we need to get the third side first (the hypotenuse side) using the Pythagoras theorem. According to the theorem:

[tex]c^2=a^2+b^2[/tex]

Given

a = 5 cm

b =12 cm

[tex]c^2=5^2+12^2\\c^2=25+144\\c^2=169\\c=\sqrt{169}\\c=13 cm[/tex]

Perimeter of the right triangle = a + b + c

Perimeter of the right triangle = 5 cm + 12 cm + 13 cm

Perimeter of the right triangle = 30 cm

Hence the perimeter of the right triangle is 30 cm.

3) If an article is purchased for 7,500, then;

If the same article is sold for 8,400, then:

[tex]\% profit=\frac{SP-CP}{CP} \times 100[/tex]

Substitute the given parameters

[tex]\% profit=\frac{8400-7500}{7500} \times 100\\\%profit=\frac{900}{7500} \times 100 \\\%profit=\frac{900}{75}\\\% profit = 12 \%[/tex]

This shows that the profit percent is 12%

Learn more on perimeter and percentage profit here: https://brainly.com/question/23264165

https://brainly.com/question/22104935

Answer:

The minimum number of subjects needed is 385.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].

The margin of error is:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

95% confidence level

So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].

95% confidence, within 5 percentage points, and a previous estimate is not known.

The sample size is n for which M = 0.05. We don't know the true proportion, so we use [tex]\pi = 0.5[/tex]

Then

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.05 = 1.96\sqrt{\frac{0.5*0.5}{n}}[/tex]

[tex]0.05\sqrt{n} = 1.96*0.5[/tex]

[tex]\sqrt{n} = \frac{1.96*0.5}{0.05}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.96*0.5}{0.05})^2[/tex]

[tex]n = 384.16[/tex]

Rounding up:

The minimum number of subjects needed is 385.

Answer:

{(0, 0), (1, ⅔), (2, 4/3), (3, 2)…}

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Explanation:

As the graph shows, three of the four points are on the same line. That line being y = 5x. This line has slope 5 and y intercept 0.

The point not fitting this pattern is the point (5,15), so that is the final answer.

For the other three points, note that the jump from x to y coordinate is "times 5". For example, y = 5x = 5*2 = 10 for point A. In contrast, point D has a jump of "times 3" when going from x to y.

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Alternatively, you can divide each y coordinate by its corresponding x coordinate.

All results are 5 so far. Choice D doesn't follow the trend and instead has y/x = 15/5 = 3. This is another way to show that choice D is the answer.

Answer:

D

Step-by-step explanation:

Answer:

14 days

Step-by-step explanation:

Answer:

Step-by-step explanation: