Question

Show all work to multiply
(3+ square root -16) (5 – square root -25)

Answer 1

`\left(3+√(-16) \right) \left(5-√(-25) \right)\\\\=\left(3+√(-1) \cdot √(16) \right) \left(5- √(-1) \cdot √(25) \right)\\\\=(3+4i)(5-5i)~~~~~~~~~~~~~~;\left[i=√(-1) \right]\\\\=15-15i + 20i - 20i^2\\\\=15+5i -20(-1)~~~~~~~~~~~~;[i^2 =-1]\\\\=15+5i +20\\\\=35+5i`