Start learning →

Compute (3 + 5i)(2 + 6i).

A6 + 30
B-24 + 28i
C36 + 28i
D6 + 30i
Answer & Solution
Correct answer: B. -24 + 28i
(a + ib)(c + id) = (ac - bd) + i(ad + bc). **Here:** ac - bd = 3×2 - 5×6 = 6 - 30 = -24. ad + bc = 3×6 + 5×2 = 18 + 10 = 28. Result = -24 + 28i.
Practise this question with Quill — AP Intermediate 1st Year →

Keep practising Complex Numbers and Quadratic Equations

Browse all Complex Numbers and Quadratic Equations questions for AP Intermediate 1st Year, or explore more Mathematics topics.

Start a Complex Numbers and Quadratic Equations lesson →
Related questions
Identify the standard form of (-i)(2i)(-i/8)³.If x + iy = (a + ib)/(a - ib), then x² + y² equals:Compute (5 - 3i)³.Find the value of i^(-39).Express (5 + √2 i)/(1 - √2 i) in the form a + ib.The multiplicative inverse of z = 2 - 3i is:The modulus |3 + i| equals:What is i^35?