Question

Which of these strategies would eliminate a variable in the system of equations?

8x + 5y = -7
-7+ 6y = -4

Choose all answers that apply:

A. Multiply the top equation by 6, multiply the bottom equation by -5, then add the equations.

B. Multiply the top equation by 7. then add the equations.

C. Multiply the bottom equation by 8, then add the equations.

Answer 1

Answer: A multiply the top equation by 6, multiply the bottom equation by -5, then add the equations

Explanation:

8x + 5y = 7

-7x + 6y = -4

multiply the top equation by 6, the equation becomes;

48x + 30y = 42 ----------(3)

multiply the bottom equation by -5, the equation becomes;

30x - 30y = 20-------(4)

adding equation (3) and (4) together;

+30y - 30y = 0

Therefore the y variable will be eliminated from the equation

Answer 2

A.

Explanation:

multiply the to equation by 6, multiply the bottom equation by -5 (you will get +30y and -30y to eliminate each other)then add equations (you will have +48x and +45x which will be = -42 + 20)