How do I figure these 2 out.

Question

Find standard form a +bi

(4 square root -9) ( -3 square root -5)

x^2 -3x+4 evaluated for x=1+i

Answer 1

For the second one i got 1+3i is this correct

Answer 2

4 (-9)^.5 * -3 (-5)^.5

-12 (45)^.5
-12 (3*3*5)^.5
-36 sqrt 5

(1+i)^2 -3(1+i) + 4
=
1 + 2 i - 1 - 3 - 3 i + 4
=
(1 -i)

Answer 3

Doesnt i^2 equal -1