Question Detail

MTH 101 MTH 101 Past Questions Objective Question

Question

Simplify: \(\frac{(2+i)(3+2i)}{4+i}\)
Options
A \(\frac{24}{17} + \frac{23}{17}i\)
B \(\frac{23}{17} + \frac{24}{17}i\)
C \(\frac{23}{17} + \frac{3}{17}i\)
Correct Answer
D \(2 - 3i\)
Correct Answer

Option C is the correct answer.

Detailed Explanation

First multiply numerator: (2+i)(3+2i) = 6+4i+3i+2i² = 6+7i-2 = 4+7i. Then divide by (4+i): (4+7i)/(4+i) × (4-i)/(4-i) = (16 -4i +28i -7i²)/(16+1) = (16+24i+7)/17 = (23+24i)/17 = 23/17 + (24/17)i. That matches option B. Option C is 23/17 + 3/17i, which is different. So B is correct.

Hint

Multiply numerator and denominator by the conjugate of the denominator.

Question Info