Subtract the sum of `(x^2-2y^2+xy) and (y^2+z^2+xyz)` from the sum of `(z^2-2zx-xyz) and (x^2+xy)`

Subtract the sum of (x^2+2y^2+7x^2y) and (x^2-3xy^2) from the sum of (x^2-y^2-xy) and (3x^2-2y^2-7)

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) .

Subtract the sum of x^2+2x+2 and xy^2+3 from the sum of 2x^2+5x-1 and y^2+x^2y-3

Subtract 2x^2-3xy from the sum of x^2-3y^2+11xy and y^2-4x^2+9xy

Subtract the sum of 13 x-4y+7z and -6z+6x+3y from the sum of 6x-4y-4z and 2x+4y-7.

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

From the sum of 3x+2x^2-y^2 and 6y-5y^2+3x^2+4x , subtract the sum of x^2-2y^2+3x-5y and 3x^2+2y^2-4x-y

From the sum of 2y^2+3yz, -y^2-yz-z^2 and yz+2z^2, subtract the sum of 3y^2-z^2 and -y^2+yz+z^2

Subtract 4x^(2) - z^(2) from the sum of 2x^(2) + 3y^(2) - 4z^(2) and x^(2) - 2y^(2) + z^(2)

Factorise : (v) x^(2) - 2xy + y^(2) - z^(2)