Simplify
Y [x+y^2+y]/y+1 +x ÷4y^2-3yx-7y^2/y^2-x^2 × 4y-7x/x+y^2
Eeeekk! Where are the parentheses?
And does that initial "Y" belong there?
I shall parse the above as
(y[x+y^2+y]/(y+1)+x) ÷ ((4y^2-3yx-7y^2)/(y^2-x^2) × (4y-7x)/(x+y^2))
= ((x^2 + xy^2 - xy - y^3)(2xy + x + y^2 + y^3))/(3y(y+1)(4y-7x))
Somehow I don't think that's what you had in mind. How about
(y[x+y^2+y]/(y+1)+x) ÷ ((4y^2-3yx-7y^2)/(y^2-x^2)) × (4y-7x)/(x+y^2)
= -((7x^2 - 11xy + 4y^2)(2xy + x + y^2 + y^3))/(3y(y+1)(x+y^2))
Still no? How about you use some parentheses and spaces to make it clear just what you meant? Enter your expression in at wolframalpha.com and see how it gets interpreted there.