Question

(a+5b)* 8/a^2-25b^2 |
b^2-6b+9/b-7*b-7/b-3|
5a^6/b^8:(10a^3b^2)|
3x+9/x^2-2x:x+3/4x-8|
n^2-3n/64n^2-1:n^4-27n/64n^2+16n+1|
(-2a^2/-b^3)|
_1/a-6-1/a+6):2/a+6|