Question

simplify. -7i·(-8i)
-56i
56i
56
-56

Explanation:

Step1: Multiply the coefficients

Multiply -7 and -8: $(-7)\times(-8)=56$.

Step2: Multiply the imaginary units

Multiply $i$ and $i$, since $i^2=- 1$, $i\times i = i^{2}=-1$.

Step3: Combine the results

Multiply the result of step 1 and step 2: $56\times(-1)=-56$.

Answer:

-56