Question

9 = -5g -23 I don't understand how to do this and I'm trying to help my son

Answer 1

With all due respect, your parental instinct is inspiring, but if you
don't understand how to do it, then you cannot help your son.

Here is a procedure that will lead to the solution ... the one value
of  'g'  that makes the equation a true statement:

1).  Add  23  to each side of the equation.

2).  Divide each side of the equation by  5 .

3).  Multiply each side by  -1 .

Answer 2

1. 9 = -5g -23
2. 9 + 23 = -5g
3. 32 = -5g
4. -32/5 = g