You can put this solution on YOUR website! Is it the i that's confusing you? Solve it the same way you did before; i.e. the FOIL method:
5(5) = 25; 5(2i) = 10i; 5(-2i)= -10i; and -2i(2i) = -4, or -4(-1), or 4.
Here, the 10i and -10i offset each other, so your answer is
25 + 4 or 29.
The key to understanding complex numbers is to remember that by definition, i = . So anytime you see , replace it with -1.
