How much does `5x^2-8xy-6y^2` exceed `3x^2-4xy+2y^2-xy^2`?

How much does 3x^2-14xy+8y^2 exceed x^2+3xy+4y^2-2xy^2

Subtract : 5x^(2)-3xy -7y^(2) from 3x^(2)-xy-2y^(2)

Subtract the sum of x^(2)-5xy +2y^(2) and y^(2)-2xy -3x^(2) from the sum of 6x^(2)-8xy-y^(2) and 2xy-2y^(2)-x^(2) .

Add x^2+y^2+3xy-6 and 2x^2-4y^2-xy+5

How much is -x^(2)+7y^(2)-3xy less than 2x^(2)-y^(2)+xy ?

How much more than 2x^(2) + 4xy + 2y^(2) is 5x^(2) + 10xy - y^(2) ?

How much bigger is 5x^(2)y^(2) - 18xy^(2) - 10x^(2)y than -5x^(2) + 6x^(2)y - 7xy ?

What must be added to 2x^(2)-3xy+5y^(2) to get x^(2)-xy-y^(2) ?

Multiply : 5x^(2) - 8xy + 6y^(2) - 3 by -3xy

2x^2+6xy+5y^2=1, then