👤

Daca x+y=4 si x²+y²=12, calculati x-y.

Răspuns :

Bună!
x+y=4
x^2+y^2=12
x=?
y=?
x^2+y^2=x×x+y×y=x×y(x+y)=x×y×4=4yx
(x+y)(x-y)=12—>4(x-y)=12—>x-y=3