Question

xy=10 e x-y= 40 resolva x^2+y^2

Answer 1

xy=10 e x-y= 40 resolva x^2+y^2
vamos densevolver o x-y.
(x-y)²=x²-2xy+y² produtos novaveis. xy=10 e x-y=40
   40²=x²-2.10 + y²
 1600=x²+y²-20
1600+20=x²+y²
x²+y²=1620