Question

X + 3y = 18
-X - 4y = -25

Answer 1

x = -3

y= 7

Explanation:

x + 3y=18 ----(1)

-x - 4y=-25 -----(2)

from equation (1)

x = 18 - 3y ---(3)

putting equation (3) into equation (2)

-(18 - 3y) - 4y = -25

18 + 3y -4y = -25

3y - 4y = -25 - 18

-y = -7

y = 7 ✓

Putting y=7 into equation (1)

x + 3(7) = 18

x + 21 = 18

x = 18 - 21

x = -3 ✓

Answer 2

-y=-7
Y=7
-x-4(-7)=-25
-x+28=-25
-x=3
X=-3