College math
posted by Jackie on .
8i(2i7)

All these complex value problems can be treated just like polynomials, where the reals and imaginaries have to be treated separately
8i(2i)  8i(7)
16i^2 + 56i
16 + 56i
Don't forget that i^2 = 1
also key: (a+bi)(abi) = a^2  b^2i^2 = a^2+b^2