Question

(8.5−1.8i)−(−1.3+2.7i)(8.5−1.8𝑖)−(−1.3+2.7𝑖)

Answer 1

Compute step by step.

Let A = 8.5 − 1.8i and B = −1.3 + 2.7i.

First compute B·A:
(−1.3 + 2.7i)(8.5 − 1.8i)
= (−1.3·8.5 + 2.7·(−1.8)·i^2) + (−1.3·(−1.8) + 2.7·8.5)i
= (−11.05 + 4.86) + (2.34 + 22.95)i
= −6.19 + 25.29i.

Now evaluate (A) − (B·A) − (B):
= (8.5 − 1.8i) − (−6.19 + 25.29i) − (−1.3 + 2.7i)
= 14.69 − 27.09i + 1.3 − 2.7i
= 15.99 − 29.79i.

Answer: 15.99 − 29.79i.