Answer:
3x²-21
Explanation:
-3(5-x² +2)
combine like terms in the parenthesis (5 and 2=7)
-3(-x² +7)
distribute the 3 so multiply -3 and -x² and 3 and 7
-3(-x²) = 3x² because a double negative is a positive
-3(7) = -21 because a negative and positive is a negative