Question

Question super simple but confused me >.< (–5 + 3i) ⋅(1 –2i) <-- i know distributive property is used but everytime I do this i keep getting like -11+13i

Answer 1

You would foil it out like you would any problem like that but you must also use the idea below:

well, we know that, \[\sqrt{-1} = i \]


so if we square both sides.

\[(\sqrt{-1)})^{2} = i^2 \]

\[-1 = i^{2}\]