Question

Daca x+y= - 2$\sqrt{3$ si x^2 -y^2=4$\sqrt{6$,atunci x-y este egal cu??

Answer 1

$\displaystyle x+y=-2 \sqrt{3} \\ x^2-y^2=4 \sqrt{6} \\ x-y=? \\ x^2-y^2=4 \sqrt{6} \\ (x+y)(x-y)=4 \sqrt{6} \\ -2 \sqrt{3} (x-y)=4 \sqrt{6} \\ x-y=- \frac{4 \sqrt{6} }{2 \sqrt{3} } \\ x-y=-2 \sqrt{2}$