Question

Express (4+7i)(2-i) in the form a+ib​

Answer 1

(4+7i)(2-i)

multiply it out

8-4i +14i -7i squared

i squared is the same as -1

8-4i+14i-7(-1)

8+7-4i+14i

15+10i

divide by common factor which is 5 in this case

3+2i