Question

(q^(-2)-r^(-2))/q^(-1)-r^(-1))

Answer 1

(q^-1 +r^-1)(q^-1 -r^-1)/(q^-1/2 +r^-1/2)(q^-1/2 -r^-1/2)

(q^1/2 +r^1/2)(q^1/2 -r^1/2)

Answer 2

r+q/qr

Answer 3

Its a difference of two squares issue,

Answer 4

yea I have no Idea how to come up with the answer but I do know the answer is r+q/qr