Question

What is the standard form of (1 7i)(3 − i)?(-10 − 10i)(-4 − 10i)(10 20i)(20 10i)

Answer 1

10 +20i you just multiply and look what to write simply

Answer 2

Standard form of (1 +7i)(3 − i) is:

10+20i

Explanation:

We have to multiply (1+7i) and (3-i)

(1+7i)(3-i)=1(3-i)+7i(3-i)

= 3-i+21i-7i²

=3+20i+7 (since, i²= -1)

=10+20i

Hence, standard form of (1 +7i)(3 − i) is:

10+20i