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3 years ago

Use elimination to solve and match each system of equations to the correct solution.

Mathematics

1 answer:

podryga [215]3 years ago

7 0

$\begin{cases}2x-9y=-51\\2x-3y=-9\end{cases}\\\\\\\begin{cases}(2x-9y)(-1)=-51(-1)\\2x-3y=-9\end{cases}$

$\begin{cases}-2x+9y=51\\2x-3y=-9\end{cases}$ (adding the second equation to the first one)

$\begin{cases}\qquad6y=42\\2x-3y=-9\end{cases}\\\\\\\begin{cases}\qquad y=7\\2x-3y=-9\end{cases}\\\\\\\begin{cases}y=7\\2x-3(7)=-9\end{cases}\\\\\\\begin{cases}y=7\\2x-21=-9\end{cases}\\\\\\\begin{cases}y=7\\2x=12\end{cases}\\\\\\\begin{cases}x=6\\y=7\end{cases}$

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The area of a circular table cloth is 1,384.74 inches square. Using 3.14 for LaTeX: \pi

leonid [27]

Answer:

radius = 21

circumference = 138.88

Step-by-step explanation:

First divide the area by 3.14, this equal 441

441 is your radius squared.

Then you have to find the root of 441 which is 21.

radius = 21

diameter = twice the radius or 2 * radius

diameter = 21 * 2 = 42

diameter = 42

Then plug 42 in your circumference formula.

Which is then C = 3.14(42).

Which means the circumference is 131.88.

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2 years ago

Find the measure of arc EC.

miss Akunina [59]

Answer:

Step-by-step explanation:

$7x = (90 + 5x) \times \frac{1}{2}$

$7x = {2.5x} + 45$

$4.5x = 45$

$x = 10$

Plug 10 in for x.

$5(10) = 50$

8 0

3 years ago

The equation line l is given by the equation y= 7/4x+3. line m goes through the point ( –1,4) and is perpendicular to line l whi

mr_godi [17]

We determine line m as follows:

*First, by theorem we have the following:

$m_1=-\frac{1}{m_2}$

Here m1 & m2 are the slopes of two perpendicular lines. For all lines that are perpendicular that is true, so we calculate the slope of line m using the slope of the function given [Which has a slope of 7/4]:

$m_1=-\frac{1}{\frac{7}{4}}\Rightarrow m_1=-\frac{4}{7}$

So, the slope of line m is -4/7. Now, using this slope and the point (-1, 4) we replace in the following expression:

$y-y_1=m_1(x-x_1)$

Here x1, y1 & m1 are the x-component of the point, the y-component of the point, and the slope of the line respectively, so we replace and solve for y:

$y-4=-\frac{4}{7}(x-(-1))\Rightarrow y-4=-\frac{4}{7}x-\frac{4}{7}$ $\Rightarrow y=-\frac{4}{7}x+\frac{24}{7}$

And that last function of y is the line m.

8 0

1 year ago

I need help solving it

Oxana [17]

7. the last one

I = P R T

I = 15.75 P = 500 R = unknown T = 6

15.75 = 500 (r) (6)

divide the T and I

15.75 ÷ 6 = 500 (r) (6) ÷6

2.62 = 500 (r) *get rid of the six*

divide the P with new answer

2.62 ÷ 500 = 500 ÷ 500 *get rid of 500*

0.00524 = r

move decimal to make it in to a percentage

5.24% = R

6 0

3 years ago

Karl has stamps in his desk drawer. The possible combinations of stamps are shown below in the attachment.

ArbitrLikvidat [17]

The table gives the different combinations of stamps Karl has

the first option says that

a. The total number of stamps is 25.

according to this the addition of stamps for each combination should be 25

1st combination is 18 + 17 = 35

therefore this statement is wrong as the addition of stamps is 35 stamps

b. The total value of the stamps is $18.75.

lets check the first combination

18 x $ 0.45 + 17 x $ 0.65 = 8.1 + 11.05 = $19.15

so this statement too is wrong

c. The total number of stamps is 35.

as calculated above we know that the sum of the stamps in the first combination is 35

so lets check for the other combinations

20 + 15 = 35

22 + 13 = 35

25 + 10 = 35

so the answer is 35

this statement is correct

d.The total value of the stamps is $19.15

lets check the value for the third combination

22 x 0.45 + 13 x 0.65 = 9.9 + 8.45 = $18.35

this value isnt equal to $ 19.15

therefore this statement too is wrong

correct answer is C

4 0

3 years ago

Read 2 more answers