Question

Làm em phần c và f ạ, làm chi tiết ạ

Answer 1

giải bài trong trang giúp mình ạ,cảm ơn

 

Answer 2

\(c,A-C+B=16x^4-8x^3y+7x^27^2-9y^4-\left(5x^3y+3x^27^2+17y^4+1\right)+\left(-15x^4\right)+3x^3y-5x^2y^2-6y^4\)

\(=16x^4-8x^3y+7x^2y^2-9y^4-5x^3y-3x^2y^2-17y^4-1+\left(-15x^4\right)+3x^3y-5x^2y^2-6y^4\)

\(=\left(16x^4-15x^4\right)-\left(8x^3y-5x^3y+3x^3y\right)+\left(7x^2y^2-3x^2y^2-5x^2y^2\right)-\left(9y^4-17y^4-6y^4\right)-1\)

\(=x^4-6x^3y+\left(-1x^2y^2\right)-\left(-14y^4\right)-1\)

\(=x^4-6x^3y-1x^2y^2+14y^4-1\)

\(=x^4+14y^4-6x^3y-1x^2y^2-1\)

 

\(f,7A-B-C-9=7.16x^4-8x^3y+7x^2y^2-9y^4-\left(-15x^4+3x^3y-5x^2y^2-6y^4\right)-\left(5x^3y+3x^2y^2+17y^4+1\right)-9\)

\(=112x^4-8x^3y+7x^2y^2-9y^4+15x^4-3x^3y+5x^2y^2+6y^4-5x^3y-3x^2y^2-17y^4-1-9\)

\(=\left(112x^4+15x^4\right)-\left(8x^3y-3x^3y-5x^3y\right)+\left(7x^2y^2+5x^2y^2-3x^2y^2\right)-\left(9y^4+6y^4-17y^4\right)-\left(1-9\right)\)

\(=127x^4+9x^2y^2-\left(-2y^4\right)-\left(-8\right)\)

\(=127x^4+9x^2y^2+2y^4+8\)

\(=127x^4+2y^4+9x^2y^2+8\)