Question

lessons 3 and 4 practice
which expression is equivalent to $2i(5 + 3i)$?
a. $-6 + 10i$
b. $6 + 10i$
c. $-10 + 6i$
d. $10 + 6i$

Explanation:

Step1: Distribute $2i$ to each term

$2i(5 + 3i) = 2i \times 5 + 2i \times 3i$

Step2: Calculate each product

$2i \times 5 = 10i$, $2i \times 3i = 6i^2$

Step3: Substitute $i^2=-1$

$6i^2 = 6\times(-1) = -6$

Step4: Combine the results

$-6 + 10i$

Answer:

A. $-6 + 10i$