化简1(.a-b)/(√a+√b)

题目

化简1(.a-b)/(√a+√b)
2.(3+√3+√6)/(2+√2+√6)
3.(5+√6+√10+√15)/(√5+√2)

答案

1(.a-b)/(√a+√b)
=(√a+√b)(√a-√b))/(√a+√b)
=√a-√b
2.(3+√3+√6)/(2+√2+√6)
=√3(√3+1+√2)/[√2(√2+1+√3)]
=√3/√2
=√3*√2/(√2*√2)
=√6/2
3.(5+√6+√10+√15)/(√5+√2)
=(5+√10+√6+√15)/(√5+√2)
=[√5(√5+√2)+√3(√2+√5)]/(√5+√2)
=[(√5+√3)(√2+√5)]/(√5+√2)
=√5+√3