Question

Rút gọn biểu thức

2x(3x^3-x)-4x^2(x-x^2+1)+(x-3x^2)x

Answer 1

2x(3x³-x)-4x²(x-x²+1)+(x-3x²)x

=6x⁴-2x²+4x⁴-4x³-4x²+x²-3x³

=(6x⁴+4x⁴)+(-4x³-3x³)+(-4x²-x²)

=10x⁴-7x³-5x²

 

Answer 2

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

\(=10x^4-7x^3-5x^2\)