A - B = (x3y - 2xy + 5xy2 - 3x2y2 - 1) - (-2x3y - xy2 + 2x2y2 - xy + 8)
= x3y - 2xy + 5xy2 - 3x2y2 - 1 + 2x3y + xy2 - 2x2y2 + xy - 8
= (x3y + 2x3y) + (-2xy + xy) + (5xy2 + xy2) + (-3x2y2 - 2x2y2) + (-1 - 8)
= 3x3y - xy + 6xy2 - 5x2y2 - 9
a-b=(x^3y-2xy+5xy^2-3x^2y^2-1)-(-2x^3y-xy^2+2x^2y^2-xy+8)
=x^3y-2xy+5xy^2-3x^2y^2-1+2x^3y+xy^2-2x^2y^2+xy-8
=x^3y+(-2xy+xy)+(5xy^2+xy^2)+(-3x^2y^2-2x^2y^2)+(-1-8)
=x^3y-1xy+6xy^2-5x^2y^2-9
\(A-B=(x^3y-2xy+5xy^2-3x^2y^2-1)-(-2x^3y-xy^2+2x^2y^2-xy+8)\)
\(=(x^3y+2x^3y)+(-2xy+xy)+(5xy^2+xy^2)+(-3x^2y^2-2x^2y^2)+(-1-8)\)
\(=3x^3y-xy+4xy^2-5x^2y^2-9\)
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a-b=(x^3y-2xy+5xy^2-3x^2y^2-1)-(-2x^3y-xy^2+2x^2y^2-xy+8)
=x^3y-2xy+5xy^2-3x^2y^2-1+2x^3y+xy^2-2x^2y^2+xy-8
=(x^3y+2x^3y)+(-2xy+xy)+(5xy^2+xy^2)+(-3x^2y^2-2x^y^2)+(-1-8)
=3x^3y-xy+6xy^2-5x^2y^2-9
\(A-B=(x^3y-2xy+5xy^2-3x^2y^2-1)-(-2x^3y-xy^2+2x^2y^2-xy+8)\)
\(=x^3y-2xy+5xy^2-3x^2y^2-1+2x^3y+xy^2-2x^2y^2+xy-8\)
\(=(x^3y+2x^3y)+(-2xy+xy)+(5xy^2+xy^2)+(-3x^2y^2-2x^2y^2)+(-1-8)\)
\(=3x^3y-xy+6xy^2-5x^2y^2-9\)
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