Elimination Method

[collograph]

Can someone double check this for me- to make sure that it is done correctly- (and if not- help to point me in the right direction)...thanks.



-x-y=-5 and 2x-y=4

(-1)-x-y=-5
-y(-1)
x+y=5
2x-y=4
3x=9
x=3


2x-y=4
2(3)-y=4
6-y=4
6=4+y
2=y

x=3
y=2

[stapel_eliz]

You can check the answer to any "solving" problem by plugging it back into the original exercise, and verifying that it works. In your case:

. . . . .-(3) - (2) = -3 + (-2) = -5 (checks)

. . . . .2(3) - (2) = 6 - 2 = 4 (checks)

Since your solution checks, it must be correct. Good job!