выполните действия
xy+y^2 y^2
1)----------- : --------
9x^2 3x

5x+1 x+17
-------- + ---------
5x-20 20-5x

1
(xy+y²)/9x²:y²/3x=y(x+y)/9x² *3x/y²=(x+y)/3xy
2
(5x+1)/(5x-20)+(x+17)/(20-5x)=(5x+1)/(5x-20) -(x+17)/(5x-20)=
=(5x+1-x-17)/(5x-20)=(4x-16)/(5x-20)=4(x-4)/5(x-4)=4/5