Question

Q. 5 it's urgent please help me

Answer 1

for rationalizing denominator
multiply denominator by its conjugate

in 2nd. if u multiply by conjugate u will get
root7 + root6/7-6
= root 7 - root 6

same as third u will get root 5 -root2/ 3

same as fourth root 7 + 2 / 3

Answer 2

1) 1/√7×√7/√7=√7/7
2)1/√7-√6×√7+√6/√7+√6=√7+√6
3)1/√5+√2×√5-√2/√5-√2=√5-√2/3
4)1/√7-2×√7+2/√7+2=√7+2/3