1.9/a^2+3a-3/a

2. a^2+y^2/ay-y^2-20/a-y

3. a^2+b^2/2a^2+2ab+b/a+b

4.4y/y^2-x^2-2/y-x

5.6a/a^2-b^2-3/a-b

1) 9/a (a+3) - 3/a = (9-3a-9) / a (a+3) = - 3a/a (a+3) = - 3 / (a+3)

2) (a²+y²) / y (a-y) - 20 / (a-y) = (a²+y²-20y) / y (a-y)

Если спутали и должно быть вместо 20 2 а, то

ответ (a²+b²-2ay) / (-y (a-y) = (a-y) ²/y (a-y) = (a-y) / y

3) (a²+b²) / 2a (a+b) + b / (a+b) = (a²+b²+2ab) / 2a (a+b) = (a+b) ²/2a (a+b) = (a+b) / 2a

4) 4y / (y-x) (y+x) - 2 / (y-x) = (4y-2y-2x) / (y-x) (y+x) = (2y-2x) / (y-x) (y+x) = 2 (y-x) / (y-x) (y+x) = 2 / (y+x)

5) 6a / (a-b) (a+b) - 3 / (a-b) = (6a-3a-3b) / (a-b) (a+b) = (-3a-3b) / (a-b) (a+b) = - 3 (a+b) / (a-b) (a+b) =

=-3 / (a-b) = 3 / (b-a)