How do you solve (-4-6i)^2 help please

i did this and i know its completely wrong
(-4-6i)^2
-16-36i^2
-16-36(-1)
-16+36= 20 <=== so wrong

when you square a binomial you get 3 terms, not 2.

(-4 – 6i)² =
(-4)² + 2(-4)(-6i) + (-6i)² =
16 + 48i + 36i² =
16 + 48i – 36 =
-20 + 48i

(-4 - 6i)²
= (-4 - 6i)(-4 - 6i) {when squaring a binomial, multiply it by itself}
= -4(-4) - 4(-6i) - 6i(-4) - 6i(-6i) {used foil method}
= 16 + 24i + 24i + 36i² {multiplied through}
= 16 + 48i + 36(-1) {i² is -1}
= 16 + 48i - 36 {multiplied 36 by -1}
= -20 + 48i {combined like terms}

http://www.algebrahouse.com

-20+48i

(-4-6i)^2 = (-4-6i)(-4-6i)=16+48i+36=52+48i