Question

How do you simplify `(10 - 4i) - (7 + 3i)`?

Answer 1

`3-71`

Explanation:

`(10-4i)-(7+3i)`
`color(white)("XXX")=color(red)(10-7color(blue)( -4i-3i)`

`color(white)("XXX")=color(red)(3)color(blue)(-7i)`

Answer 2

`3-7i`

Explanation:

You can sum two complex numbers simply by summing the real and imaginary parts.

The real part of the first number is `10`, the real part of the second one is `-7`. Summing, you have `10-7=3`

Same goes for the imaginary parts: the imaginary coefficient of the first number is `-4`, the coefficient of the second number is `-3` (remember that there's a minus sign in front of the whole expression!). Summing, you have `-4-3=-7`.