Question 46792
Use FOIL and the rules that:
{{{(sqrt(-1))= i)}}}
and (i)(i)= {{{(i^2)}}}= -1

56 + 48i + 63i + 54(i)(i)
56 + 48i + 63i + 54 {{{(i^2)}}}
56 + 48i + 63i + (54)(-1)
56 + 48i + 63i - 54
56 + 111i - 54
56 + 111i - 54
2 + 111i