Question

Solve the system of equations.
3x+6y=21

–5x+2y=13

Answer 1

Solve by substitution or elimination.

From 3x + 6y = 21, divide by 3: x + 2y = 7, so x = 7 − 2y.

Substitute into −5x + 2y = 13:
−5(7 − 2y) + 2y = 13
−35 + 10y + 2y = 13
12y = 48 ⇒ y = 4.

Then x = 7 − 2(4) = −1.

Solution: x = −1, y = 4.