Simplify the following :
`2x^(2) + 3y^(2) - 5xy +5x^(2) - y^(2) + 6xy - 3x^(2)`

Simplify the following (2x^(2) - 3xy) (4x+5y)

Simplify the following : 3xy^(2) - 5x^(2)y + 7xy - 9xy^(2) - 4xy + 6x^(2)y

Simplify the following 2/3 x^(3) yz^(2) div 5/2 xy^(3)z

Simplify the following (2x - 3y ) (4x - 5y)

Evaluate : 3x^(2) + 5xy - 4y^(2) + x^(2) - 8xy - 5y^(2)

Add the following expressions using horizontal method : -x^(2)y + xy^(2) + 2xy , 3x^(2) y + 4xy^(2) + 5xy and 7x^(2)y - 10xy^(2) - xy

Add the following : 5xy , - 7xy and 3x^(2)

Add the following expressions: x^(2)-2xy+3y^(2), 5y^(2)+3xy-6x^(2)

Subtract : 2x^(2) + 3xy - 4y^(2) " from " 4x^(2) - xy +3y^(2)

Simplify using following identiy: (a +- b) (a^(2) ab + b^(2)) = a^(3) +- b^(3) (2x + 3y) (4x^(2) - 6xy + 9y^(2))