Question

4x + y = 4

2x + 6y = 24

Which action creates an equivalent system that will eliminate one variable when they are combined?

Answer 1

(There's actually a few ways of solving this, but here's one)

Multiplying the second equation by 2.

EDIT: Because the question says it will eliminate a variable "when combined", implying adding the systems together. The actual correct answer is multiplying the second equation by -2.

(multiplying the second equation by -2 is the actual answer, my apologies)

Explanation:

So it's clear that they are referring to the elimination method and not the substitution method for solving systems of equations.

In the elimination method, you subtract 2 equations in the hopes of the elimination of a variable.

If you multiply the second equation, 2x + 6y = 24, by 2, you get, 4x + 12y = 48.

This is helpful because when you subtract this from the first one, you eliminate x.

4x + y = 4

-(4x + 12y = 48)

is

-11y = -44