Question

If a+b=5 and ab=2,find the value of using identity (a-b)^2.​

Answer 1

Answer:

We know a+b = 5

Hence (a+b)^2 = 5^2

a^2 + b^2 + 2ab = 25

a^2+b^2 +2ab -2ab + 2ab = 25 (Just add and subtract 2ab)

a^2 + b^2 -2ab + 4ab = 25

(a-b)^2 + 4(2) = 25

(a-b)^2 = 25-8

(a-b)^2 = 17

(a-b) = √17