Question

Solve the system of equations.
–9x+y=12
–
9
𝑥
+
𝑦
=
12

2x+4y= −28
2
𝑥
+
4
𝑦
=

−
28

Answer 1

Solve by substitution.

From the first equation, -9x + y = 12, so y = 12 + 9x.
Substitute into the second: 2x + 4(12 + 9x) = -28
=> 2x + 48 + 36x = -28
=> 38x + 48 = -28
=> 38x = -76
=> x = -2.

Then y = 12 + 9(-2) = 12 - 18 = -6.

Solution: (x, y) = (-2, -6).