a+b = 6 এবং a-b = 2 হলে, ab = কত?

a+b = 6 এবং a-b = 2 হলে, ab = কত?

A 8

B 4

C 5

D 6

Solution

Correct Answer: Option A

4ab = (a+b)^2 - (a-b)^2 = (6)^2 - (2)^2 = 36 - 4

=> 4ab = 32

ab = 8