(-4-21)(-4+2i)=

Solution for (-4-21)(-4+2i)= equation:

Simplifying
(-4 + -21)(-4 + 2i) = 0

Combine like terms: -4 + -21 = -25
(-25)(-4 + 2i) = 0
(-4 * -25 + 2i * -25) = 0
(100 + -50i) = 0

Solving
100 + -50i = 0

Solving for variable 'i'.

Move all terms containing i to the left, all other terms to the right.

Add '-100' to each side of the equation.
100 + -100 + -50i = 0 + -100

Combine like terms: 100 + -100 = 0
0 + -50i = 0 + -100
-50i = 0 + -100

Combine like terms: 0 + -100 = -100
-50i = -100

Divide each side by '-50'.
i = 2

Simplifying
i = 2