Respuesta :

Answer:

- 14 + 18i

Step-by-step explanation:

Note that i² = ([tex]\sqrt{-1}[/tex] )² = - 1

Given

4i(- i + 3) - 3(6 - 21) ← distribute both parenthesis

= - 4i² + 12i - 18 + 6i

= - 4(- 1) - 18 + 18i

= 4 - 18 + 18i

= - 14 + 18i