1
2√a+6√a-7√a=√a 2
2
√32+√18-√50=4√2+3√2-5√2=2√2 1
3
(7√2-√98+√10)*√2=(7√2-7√2+√10)*√2=√20=2√5 3
4
(√5-√18)(√5-2√2)=(√5-3√2)(5-2√2)=5-2√10-3√10+12=17-5√10 2
5
(5√6-6√2)²=150-60√12+72=222-120√3 4
B1
3/4√5=3√5/4*5=3√5/20
B2
6/(5-2√6)=6(5+2√6)/[(5-2√6)(5+2√6)]=6(5+2√6)/(25-24)=6(5+2√6)