Question

Se (x-y)^2=25 e xy=24 calcule o valor de x^2+y^2

Answer 1

(x-y)² = 25
xy = 24
x²+y² = ...

x²-2xy+y² = 25
x²-2*24+y² = 25
x²-48+y² = 25
x²+y² = 25+48
x²+y² = 73