Question

If a^2 + b^2 = 29 and ab = 10 ; find : (i) a + b (ii) a – b

Answer 1

(i) a² + b² + 2ab = 29 + 20

(a+b)² = 49

∴a+b = 7

(ii) a² + b² - 2ab = 29 - 20

(a-b)² = 9

∴a-b=3

[If you don't understand what I have done in the second step of both questions, I have used algebraic identities.]