Question

Solve the system of equations.
x−3y=18
𝑥
−
3
𝑦
=
18

7x−5y=46

Answer 1

From x − 3y = 18, x = 18 + 3y. Substitute into 7x − 5y = 46:
7(18 + 3y) − 5y = 46
126 + 21y − 5y = 46
16y = −80 ⇒ y = −5.
Then x = 18 + 3(−5) = 3.

Solution: (x, y) = (3, −5).