Question

if x+y=12 and xy=14, find the value of x square + y square

Answer 1

your ans

given:-

x+y=12

xy=14

apply:- (x+y)2=x2+y2+2xy

(12)2=x2+y2+2×14

144-28=x2+y2

116=x2+y2

Answer 2

Equation 1: (x + y) = 12 ------- square both sides: (x + y)^2 = 12^2 ----> x^2 + 2(x)(y) + y^2 = 144 

Equation 2: (x)(y) = 14 
Take x(y) in equation 2 and substitute it as 14 into x(y) in equation 1: 

x^2 + 2(14) + y^2 = 144 
subtract 2(14) which is 28 to both sides of the equation: 

x^2 + y^2 = 116
--------Hope it helps--------