Answer: 336+6i
The key to solving this problem is to choose which parts you should solve first.
2i(3-4i)+8(4-5i)(4+5i)
let's divide this expression to three parts:
2i(3-4i), 8 and (4-5i)(4+5i)
first let's solve 2i(3-4i):
2i(3-4i) =
2i × 3 + 2i × -4i =
6i - 8i² =
6i + 8
(4-5i)(4+5i):
(4-5i)(4+5i) =
16 + 20i - 20i -25² =
16 + 25 =
41
8(4-5i)(4+5i):
8(4-5i)(4+5i) = 8 × 41 = 328
Now let's put back these parts:
2i(3-4i)+8(4-5i)(4+5i) =
6i + 8 + 328 =
6i +336 OR 336 +6i
