Question

Cho đa thức A= 7x^2y^3-6xy^4+5x^3y-1 B=-x^3y-7x^2y^3+5-xy^4 Tính A+B

Answer 1

A +B=  \(\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ 7x^2y^3-6xy^{4^{ }}+5x^3y-1-x^3y-7x^2y^{3^{ }}+5-xy^4\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ =\left(7x^2y^3-7x^2y^3\right)+\left(-6xy^{4^{ }}-xy^4\right)+\left(5x^3y-x^3y\right)+\left(-1+5\right)\\ \\ \\ \\ \\ \\ \\ \\ \\ \\ =7xy^4+4x^3y+4\)

Answer 2

Ta có: A+B

\(=7x^2y^3-6xy^4+5x^3y-1-x^3y-7x^2y^3+5-xy^4\)

\(=\left(7x^2y^3-7x^2y^3\right)-\left(6xy^4+xy^4\right)+\left(5x^3y-x^3y\right)+\left(5-1\right)\)

\(=-7xy^4+4x^3y+4\)