Question

What is the solution to the system of equations?

3x+10y=-47
5x - 7y=40
O (1.-5)
O (1,5)
0 (-1,-5)
0 (-1,5)

Answer 1

x=1 ,y=-5

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