Répondre :
(√5-√2)/√3=(√5-√2)(√5+√2)/(√3(√5+√2)
=(5-2)(√3(√5+√2)
=(√3)/(√5+√2)
(x²+x-6)/(x²-x-2)=((x+3)(x-2))/((x+1)(x-2))
=(x+3)/(x+1)
(x-3)(x+2)-x²+x(x-4)=x²-x-6-x²+x²-4x
=x²-5x-6
=(x-6)(x+1)
=(5-2)(√3(√5+√2)
=(√3)/(√5+√2)
(x²+x-6)/(x²-x-2)=((x+3)(x-2))/((x+1)(x-2))
=(x+3)/(x+1)
(x-3)(x+2)-x²+x(x-4)=x²-x-6-x²+x²-4x
=x²-5x-6
=(x-6)(x+1)