Question

if x+y=12 and xy=27,find the value of x square + y square​

Answer 1

$(x + y) {}^{2} = 144 \\ = > {x}^{2} + {y}^{2} + 2xy = 144 \\ = > {x}^{2} + {y}^{2} + 2(27) = 144 \\ = > \boxed{ \green{{x}^{2} + {y}^{2} = 198 }}$