Question

A student solved the problem below but made an
error.
- 3x = 12
+3 +3
x = 15​

Answer 1

Division should be used instead of multiplication

-3x=12

x=-4 (divide by -3)

Answer 2

Because -3x is one term, you need to divide both sides by -3, not add 3 to both sides:

-3x = 12

Divide both sides by -3:

-3x/3 = 12/-3

x = -4