Question

Solve for x and y: x-3y=-8 3x+2y=31

Answer 1

x - 3y = -8
3x + 2y = 31
———————
3x - 9y = -24
3x + 2y = 31
———————
-11y = -55
y = 5

x - 3y = -8
x - 3(5) = -8
x - 15 = -8
x = 7

(x, y) = (7, 5)

Answer 2

x = 3y - 8

Plug this in for variable x in equation [2]
[2] 3•(3y-8) + 2y = 31 [2] 11y = 55 Solve equation [2] for the variable y

[2] 11y = 55 [2] y = 5 // By now we know this much : x = 3y-8 y = 5// Use the y value to solve for x
x = 3(5)-8 = 7 Solution : {x,y} = {7,5} Processing ends successfully