Question

Show all work to multiply: (3+sqrt(-16)(6-sqrt(-64)

Please only CORRECT ANSWERS. Don't answer if you don't know.

Answer 1

50

Explanation:

Complex numbers:

i^2 = -1

First simplify the radicals. Then use FOIL method

`\sf (3 + √(-16))(6-√(-64)) = (3 +√(i^2*4^2))(6-√(i^2*8^2))`

= ( 3 + 4i)(6 -8i)

= 3*6 - 3*8i + 4i*6 - 4i*8i

= 18 - 24i + 24i - 32i^2

= 18 - 24i + 24i - 32*(-1)

= 18 - 24i +24i + 32

= 18 + 32 - 24i + 24i

Combine like terms,

= 50