Solve by elimination method.

Question

7r-3s=14
3r+7s=64

Could never figure out the elimination method. Would love some help with this one. Thanks

Answer 1

21r - 9s = 42
(I multiplied the first eq. by 3)
21r + 49s = 448
(I multiplied the second equation by 7)

58s = 406
(I subtracted the third equation from the fourth, to eliminate r.)

The remaining steps are easy.

s = 7

7r -21 = 14
r = 5