Is x=-8 a solution of the equation 3 (x+1) = 3x+3

It is true for all x.

Step-by-step explanation:

3 (x + 1) = 3x + 3

3x + 3 = 3x + 3

3x = 3x + 3 - 3

3x = 3x

0 = 0

It is true for all x. It means that it can be any solution for x since they would result the same.

If you choose x = - 8

3 (-8 + 1) = 3 (-8) + 3

-24 + 3 = - 24 + 3

-21 = - 21