Please tell me solution of QUESTION NUMBER-14,15.

14. x + y = 12 and xy = 14, find the value of (x²+y²)

Solution:-

Given: x + y = 12 and xy = 14

(x²+y²) = x²+y² + 2xy - 2xy = (x+y)² - 2xy = (12)² - 2(14) = 144 - 28 = 116

 

15. x - y = 7 and xy = 9, find the value of (x²+y²)

Solution:-

Given: x - y = 7 and xy = 9

(x²+y²) = x²+y² - 2xy + 2xy = (x-y)² + 2xy = (7)² + 2(9) = 47 + 18 = 65