a)√(√5-2) ×√(√5+2)= √[(√5)²-2²)]= √(5-4)=√1=1 raspuns corect b)
b) (x²-4)/(x²-x-2) : (x+2)/(x²+4x+3)=
= (x-2)(x+2)/(x²+x-2x-2) : (x+2)/(x²+3x+x+3)=
= (x-2)(x+2)/(x+1)(x-2) : (x+2)/(x+3)(x+1)=
= (x-2)(x+2)/(x+1)(x-2) × (x+3)(x+1)/(x+2)=
= x+3 raspuns corect a)
AB=5 AA'=12 d(C', AD)=√(12²+5²)=√(144+25)=√169=13 cm
h=0,6 dm = 6 cm
AB=24:6= 4 cm
A(poligonului obtinut prin sectionarea prismei cu un plan paralel cu bazele ) =4²√3/4=4√3 cm²