Question

You are given the system of equations to solve by the elimination method, which is an INCORRECT step that will NOT produce a system with the same solution? x + 2y = 7 2x − 5y = 5 A) add 5 times the first equation and 2 times the second equation B) multiply the first equation by 2 and subtract the second equation C) multiply the first equation by −2 and add the second equation D) multiply x by 2 in the first equation and subtract the second equation

Answer 1

D

Explanation:

If you're doing to multiply a value by a number, ALL terms in the equation must be multiplied by the same value otherwise you do not have a correct equation.

Answer 2

D) multiply x by 2 in the first equation and subtract the second equation

Explanation:

When you are trying to solve a system of equations you have to eliminate one of the terms so you´ll end up with only a one term equation that is solvave, in this case if you multiply X by 2 you can actually eliminate X from that equation, but by not multiplying all the terms on the equation you end up with a whole different equation and the result wont be accurate.