Question

Solve the system of equations by substitution

x+y=4
y=3x
The solution of the system is what?

Answer 1

(x, y) = (1, 3)

Explanation:

given the 2 equations

x + y = 4 → (1)

y = 3x → (2)

Substitute y = 3x into (1)

x + 3x = 4

4x = 4 ( divide both sides by 4 )

x = 1

Substitute x = 1 into (2) for corresponding value of y

y = 3 × 1 = 3

solution is (1, 3 )