PLZ HELP ON NUMBER 3 ASAP

Show your workcan a right triangle have this sides? *how to prove it without using the pythagorean theorema*

Which expression is equivalent to (4 +6i)^2? ? -20 + 48i 8 + 12i 16 - 36i 20 + 48i

Avery’s piggy bank has 300 nickels, 450 pennies, and 150 dimes. she randomly picks three coins. each time she picks a coin, she makes a note of it and puts it back into the piggy bank before picking the next coin.