(x^2-y^2/y^2*x):(x+y/x*y)= (x^2-y^2)*x*y/(y^2*x)* *(x+y)= (x+y)*(x-y)*x*y/(y^2*x)*(x+y)=
(x-y)*x*y/y^2*x= x-y/y
2)
m^3*a+a^2*m^2/m^5:m^2+a*m/a^2=
(m^3*a+a^2*m^2)*a^2/m^5*(m^2+a*m)=
a*m *(m^2+a*m)*a^2/m^5*(m^2+a*m)=
a*m*a^2/m^5=
a^3/m^4
3) (ab+b^2)*3a/3*b^3=
(ab+b^2)*a/b^3=
b (a+b)*a/b^3=
a*(a+b)/b^2
a*(a+b)/b^2+ a+b/b=
a*(a+b)+b*(a+b)/b^2=
(a+b)*(a+b)/b^2=
(a+b)^2/b^2
4) 5y*(x^2-xy)/x^2*5y=
x^2-xy/x^2=
x (x-y )/x^2=
x-y / x
x -y/x - x-y /x=0