Question

Solve the system of equations using substitution

x+y=12
y=3x

Answer 1

(3, 9 )

Explanation:

x + y = 12 → (1)

y = 3x → (2)

substitute y = 3x into (1)

x + 3x = 12

4x = 12 ( divide both sides by 4 )

x = 3

substitute x = 3 into (2) and solve for y

y = 3x = 3 × 3 = 9

solution is (3, 9 )