-3m(m+8)
a.) -3m^2 + 24
b.) 3m^2 - 24m
c.) -24m^2
d.) -4m + 5
To simplify the expression -3m(m+8), you need to apply the distributive property by multiplying -3m with each term inside the parentheses.
Step 1: Distribute -3m by multiplying it with m.
-3m * m = -3m^2
Step 2: Distribute -3m by multiplying it with 8.
-3m * 8 = -24m
Combining the terms, the simplified expression becomes -3m^2 - 24m.
Therefore, the correct answer is option b.) 3m^2 - 24m.