Помогите решить! 7 класс

1) 2ab+a^2/2b * 2b/2a^2+a

2) (x^2-y^2) : (x+2) ^2/2x

3) 2m^2 - 18/m * 2m/m+3 + 36m/m-3

4) (y/x - 2 + x/y) * x^2/x^2-y^2

5) (25/a^3-25a + 1/a+5) : (a-5/a^2+5a - a/25+5a)

1) (2ab+a²) / 2b*2b / (2a²+a) = a (2b+a) / a (2a+1) = (2b+a) / (2a+1)

2) (x²-2²) : (x+2) ²/2x = ((x-2) (x+2)) * 2x / (x+2) ² = (x-2) * 2x / (x+2) =

= (2x²-4x) / (x+2) = 2x (x-2) / (x+2)

3) 2m²-18/m*2m/m+3+36m/m-3=2m²-36/m+36

4) (y/x-2+x/y) * x² / (x²-y²) = (y²-2xy+x²) * x² / ((x-y) (x+y)) = (y-x) ²*x² / ((x-y) (x+y) =

= - (y-x) ²*x² / ((y-x) (x+y) = - x² (y-x) / (x+y)

5) (25 / (a³-25a) + 1 / (a+5)) : ((a-5) / (a²+5a) - a / (25+5a)) =

= (25 / (a (a²-5²)) + 1 / (a+5)) : ((a-5) / (a (a+5)) - a / (5 (5+a)) =

= (25+a (a-5)) / (a (a²-5²)) : ((a-5) * 5-a² / (5a (5+a)) =

= (25+a²-5a)) / (a (a²-5²)) * (5a (5+a) / (5a-25-a²)) = - (5a (5+a) / (a (a-5) (a+5)) = 5 / (a-5)