Paper 1 · Complex numbersGiven w=1+2iw = 1 + 2iw=1+2i and u=3−iu = 3 - iu=3−i, express uwuwuw in the form a+iba + iba+ib.A3−2i3 - 2i3−2iB1+5i1 + 5i1+5iC5−5i5 - 5i5−5iD5+5i5 + 5i5+5iExplanation: (3−i)(1+2i)=3+6i−i−2i2=3+5i+2=5+5i(3-i)(1+2i)=3+6i-i-2i^2=3+5i+2=5+5i(3−i)(1+2i)=3+6i−i−2i2=3+5i+2=5+5i.Derived from ZIMSEC Mathematics Paper 1, November 2017, Q1