Question

Solve the following system.

y = x + 3
4x + y = 18

(6, 3)

(3, 6)

(−3, 6)

(3, −6)

Answer 1

the answer is 3,6 this was easy

Answer 2

y = x + 3 . . . (1)
4x + y = 18 . . . (2)

Putting (1) into (2) gives
4x + x + 3 = 18
5x = 18 - 3 = 15
x = 15/5 = 3
x = 3
y = x + 3 = 3 + 3 = 6

Solution = (3, 6)