Question

x+y =12 and xy 14 find the value of x^2+y^2

Answer 1

X^2+Y^2= (X+Y)^2- 2XY Then, if x+y = 12, xy= 14 It would be, (12)^2- 2.14 = 144-28  = 116

Answer 2

see
$x + y = 12 \\ (x + y) ^{2} = {12}^{2} or144 \\ (x + y)^{2} = {x}^{2} + {y}^{2} + 2xy \: nowxy = 14so2xy = 28 \\ 144 = {x}^{2} + {y}^{2} + 28or \\ {x}^{2} + {y}^{2} = 144 - 28 = 116$