Question

(x la patrat - x ) ( x la patrat +x ) = ....

Answer 1

$( x^{2} -x)( x^{2} +x)= x^{4} -x= x^{3} ( x^{2} -x)=( x^{2} +x)( x^{2} -x)= \\ x^{4} + x^{3} - x^{3} - x^{2} = x^{4} - x^{2} = x^{2} =x*x$