What does #(3+7i)/(12+5i)# equal in a+bi form?

1 Answer
Oct 23, 2015

#(3+7i)/(12+5i) = 71/169 + 69/169i#

Explanation:

Multiply numerator and denominator by the conjugate of the denominator as follows:

#(3+7i)/(12+5i) = ((3+7i)(12-5i))/((12+5i)(12-5i))#

#=(36-15i+84i-35i^2)/(12^2-5^2i^2)#

#=((36+35) + (84-15)i)/(144+25)#

#=(71+69i)/169#

#=71/169 + 69/169i#