Question

Find the difference.

(8 - 6i) ( -1 -3i )

a) 7 - 9i
b) 9 - 9i
c) 7 - 3i
d) 9 - 3i

Thank you!

Answer 1

When we add or subtract complex numbers, we apply the same rules as operations with algebraic expressions.

That is, we treat i as x: we add or subtract the numbers together, and the x'es (that is the i's) together.

So we have,  $\displaystyle{ (8-6i)-(-1-3i)=8-6i+1+3i=9-3i$

Answer: D