3√8+√2-3√18=3·2√2+√2-3·3√2=√2(6+1-3)=-2√2
(√5-√2)²=(√5)²-2·√5·√2+(√2)²=5+2-2√10=7-2√10
(2-√3)(2+√3)=2²-(√3)²=4-3=1
3√8+√2-3√18=3·2√2+√2-3·3√2=√2(6+1-3)=-2√2
(√5-√2)²=(√5)²-2·√5·√2+(√2)²=5+2-2√10=7-2√10
(2-√3)(2+√3)=2²-(√3)²=4-3=1