x+y=8 and x-3y=-4 solved using susitution

Question

solve using subsitution

Answer 1

x + y = 8

solve for y, y = -x + 8

put this into the 2nd equation for y

x - 3(-x + 8) = -4

distribute

x + 3x - 24 = -4

combine like terms

4x - 24 = -4

add 24 to both sides

4x = 20

divide both sides by 4 and x = 5

the put 5 in for x and solve for y. y = 3

answer is (5,3)