Répondre :
calculer
A= (2√5-3)(√3+ √5)-(√3+√5)²
=2√15-3√3+10-3√5-(3+5+2√15)
=-3√3-3√5+2
B=(1- √2)(5√2+3)+(1-√2)²
=5√2+3-3√2-10+1-2√2+2
=-5
supprimer le radical du dénominateur
A= 3/(√5-2)
=3(√5+2)/(5-4)
=6+3√5
B= x/(4-√7)
=x(4+√7)/(16-7)
=4/9x+x√7/9
A= (2√5-3)(√3+ √5)-(√3+√5)²
=2√15-3√3+10-3√5-(3+5+2√15)
=-3√3-3√5+2
B=(1- √2)(5√2+3)+(1-√2)²
=5√2+3-3√2-10+1-2√2+2
=-5
supprimer le radical du dénominateur
A= 3/(√5-2)
=3(√5+2)/(5-4)
=6+3√5
B= x/(4-√7)
=x(4+√7)/(16-7)
=4/9x+x√7/9