Вычеслите a)(3+i)(3-+2i)+7; b)(i-1)^4

a)(3+i)(3-i)-(6+2i)+7 = 
(9-i^2)-6-2i+7 =
9 -(-1) -2i +1 =
-2i +11

b)(i-1)^4 =
(i^2 - 2 i +1)^2=
(-1 -2i +1)^2=
(-2i)^2 =
4*i^2 =4 * -1 = - 4