$x^4y^2+8x^3y+y-6x$ has degree 6
Work Step by Step
$$(3x^4y^2+5x^3y-3y)-(2x^4y^2-3x^3y-4y+6x)$$ $$=3x^4y^2+5x^3y-3y-2x^4y^2+3x^3y+4y-6x$$ $$=(3x^4y^2-2x^4y^2)+(5x^3y+3x^3y)+(-3y+4y)-6x$$ $$=x^4y^2+8x^3y+y-6x$$ Has degree 6 because $x^4y^2$ is the term with the largest degree. To find the degree of a term, add the degrees of each variable in the term. The degree of the expression is the degree of the term with the largest degree.