Answer:
x=1 ,y=-5
Step-by-step explanation:
3x + 10y = 47
5x - 7y = 40
____________
21x + 70y = 329. equ 1
50x - 70y = 400. equ 2
subtract equ 1 from 2
=71x = 71
divide both sides by the 71
71/71 = 71/71
x = 1
_________
to find y
substitute x into either equ 1 or equ 2
am using equ 2
5x - 7y = 40
5(1) - 7y = 40
5 - 7y = 40
7y = 5 - 40
7y = -35
divide both sides by the coffecient of y
7y/7 = -35/7
y = - 5
