-10i(5+8i)

2 answers

oh yeah it says to simplify but I have no clue at all as to how to do this it is a complex number problem I think does anyone know how to do this?(im the one that posted the question)
remember , for complex numbers
i =√-1 , and i^2 = -1

-10i(5+8i)
= -50i - 80i^2 , treating i just like any ol' variable.
= -50i - 80(-1)
= 80 - 50i