Question

Select the ordered pair from the choices below that is a solution to the following system of equations:
2x = y + 11
3y + 7 = -(1/2)x



A. (-2, -15)

B. (10, 9)

C. (4, -3)

D. (-1, -13)

Answer 1

If you multiply the second equation by a number you can make the term in x have the same value as the term in x in the first equation, but with a negative sign. The like terms in the equations can then be added and the terms in x will be eliminated. What number can be used as a multiplier?

Answer 2

Do you understand the above explanation?

Answer 3

noo

Answer 4

Start with 2x = y + 11 and solve for y


2x = y + 11

2x-11 = y + 11-11

2x-11 = y

y = 2x-11

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Now because y = 2x-11, we can replace 'y' in the second equation with 2x-11 (since they are the same thing)


3y + 7 = -(1/2)x

3(2x-11) + 7 = -(1/2)x


Now solve for x


3(2x-11) + 7 = -(1/2)x

6x-33 + 7 = -(1/2)x

6x-26 = -(1/2)x

2*6x-2*26 = -2*(1/2)x ... Note: Multiply EVERY term by the LCD 2 to clear out the fraction

12x - 52 = -x

-52 = -x-12x

-52 = -13x

-52/(-13) = x

4 = x

x = 4

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Now that we know that x = 4, we can use this to find y. Plug it into y = 2x-11 to find y.


y = 2x-11

y = 2(4) - 11

y = 8-11

y = -3


So the solutions are x = 4 and y = -3


So the solution as an ordered pair is (4,-3)

Answer 5

thanks that helped

Answer 6

I am confused. Should we be presenting model solutions thru to an answer or should we go step by step with the questioner?