Hi
If x+y=9 and xy = 20 . Find the value of x2 + y2?
x+y=9: xy=20
x+y=9 (squaring both sides)
(x+y)^2=(9)^2
x^2+y^2+2xy=81
x^2+y^2+2(20)=81
x^2+y^2=81-40
x^2+y^2=41
If x2+xy+x=12 and y2+xy+y=18 then find the value of x-y is