-18 +6g
1) To find out an equivalent expression, let's distribute the factor -3 over that parentheses, expanding that expression:
-3(4 - 2g) - 6 Distribute that factor
-12 +6g -6 Subtract those numbers
-18 + 6g
2) Hence, an equivalent expression (same value) for -3(4 - 2g) - 6 is -18 +6g