Răspuns :
8+2√15=15+2√15+1=(√15+1)²
radical(√15+1)²=√15+1
_____________
12-6√3=9-2*3√3+3=(3-√3)²
radical (3-√3)²=3-√3
_________________
17+√288=17+√2^5·3²=
17+2²·3√2=17+2·6√2=9+2·6·√2+8=(3+2√2)²
radical din (3+2√2)=3+2√2
radical(√15+1)²=√15+1
_____________
12-6√3=9-2*3√3+3=(3-√3)²
radical (3-√3)²=3-√3
_________________
17+√288=17+√2^5·3²=
17+2²·3√2=17+2·6√2=9+2·6·√2+8=(3+2√2)²
radical din (3+2√2)=3+2√2