Question 42022
First, factor the numerator and the denominator:
4r^2 - 25s^2 = (2r - 5s)(2r + 5s)
divided by 
2r^2 + 3rs - 20s^2= (2r -5) (r + 4s)
.
. 
(2r - 5s)(2r + 5s)
________________
(2r -5s) (r + 4s)
.
Cancel out (2r-5s)
.
.
= 
2r + 5s
_________
r + 4s