Question

1. 2x+7y=16
4x+3y=10


2. 5x+2y=20
7x+3y=29

Answer 1

1. 2x + 7y = 16 / * (-2)

-4x - 14y + 4x + 3y = -22
11y = -22 / :11
y = -2
4x - 6 = 10
4x = 16 / :4
x = 4
y = -2

2. 5x + 2y = 20 / * (-3)
7x + 3y = 29 / * 2
-15x - 6y = -60
14x + 6y = 58
-x = -2 / : (-1)
x = 2
14 + 3y = 29
3y = -14 + 29
3y = 15 / :3
y = 5
x = 2