Question

Find the product of the complex numbers and enter it below.

(2 - 3i )(1 + 7i )

Answer 1

(2-3i)(1+7i)

// multiply the left side through
2(1+7i) - 3i(1+7i)

// expand. remember to carry the negative
2(1) + 2(7i) - (3i)(1) - (3i)(7i)

// expand. i^2 = -1
2 + 14i - 3i - 21(-1)

// add
2 + 11i + 21

// add
23 + 11i