The equation −3x−9=−21 is solved as follows. Supply the correct numbers to complete the solution.(1 point)

−3x−9=−21
−3x=
Add 9 to both sides.

1 answer

To solve the equation, we can start by adding 9 to both sides of the equation:

−3x - 9 + 9 = -21 + 9

This simplifies to:

-3x = -12