Question

If you wanted to eliminate the y variable by adding the two equations in the following system, what could be your first step?

x − y = 6
4x − 3y = 12

Add the two equations together

Multiply the first equation by −4

Multiply the first equation by 3

Multiply the first equation by −3

Answer 1

multiply first equn. by 3

Answer 2

all of the bottom three are acceptable steps.

Answer 3

sorry - u are adding - its multiply first equn. by -3

Answer 4

If u hv to eliminate by adding, then the two y terms should be of opposite signs i.e. if one is positive the other has to be negative....

so the correct ans is "Multiply the first equation by −3 "

This will make the y terms in first equation as + 3y
This when added to the - 3y in the second equation will eliminate the y term