Question

Answer 1

a: \(M=P+Q=3x^2y-2x+5xy^2-7y^2+3xy^2-7y^2-9x^2y-x-5\)

\(=-6x^2y+8xy^2-3x-14y^2-5\)

b: M=Q-P

\(=3xy^2-7y^2-9x^2y-x-5-3x^2y+2x-5xy^2+7y^2\)

\(=-2xy^2-12x^2y+x-5\)

Answer 2

\(M=P+Q=3x^2y-2x+5xy^2-7y^2+3xy^2-7y^2-9x^2y-x-5=-6x^2y+8xy^2-3x-7y^2-5\)

\(M=Q-P=3xy^2-7y^2-9x^2y-x-5-\left(3x^2y-2x+5xy^2-7y^2\right)=-12x^2y-2xy^2+x-5\)