Question 318975
1. 10y^/9v^2*81v^4/100y;
10y^2+81v^4 / 9v^2*100y
y/10 *9v^2
9v^2y/10
..

2.z^2-z-6/z^2-4z+4*z-2/z-3;
(z-3)(z+2)/(z-2)^2 *z-2 /z-3
(z-3)(z+2)(z-2)/(z-2)^2*(z-3)
=(z+2)/z-2)
.. 
y^2-81/y divided by y-9/y+6; 
(y+9)(y-9) /(y-9)/(y+6)
(y+9)/(y+6)

4.x^2-4/25x+50 divided by x-2/10
(x+2)(x-2)/(x-2)/10
(x+2)/10

5.r^2+62/r^2+3r-18 divided by r/r+3
r^2+62/(r+6)(r-3) *(r+3)/r