Question

1)Tính

a-(2x-y)(4x²-2xy+y²)

b-(6x⁵y²-9x⁴y³+15x³y⁴):3x³y²

c-(2x³-21x²+67x-60):(x-5)

d-(x⁴+2x³+x-25):(x²+5)

e-(27x³-8):(6x+9x²+4)

Answer 1

a)\(\left(2x-y\right)[\left(2x\right)^2-2.2x.y+y^2]\)

\(=\left(2x-y\right)^3\)

b)\(2x^2-3xy+5y^2\)

c)\(2x^3-10x^2-11x^2+55x+12x-60\)

\(=2x^2\left(x-5\right)-11x\left(x-5\right)+12\left(x-5\right)\)

\(=\left(x+5\right)\left(2x^2-11x+12\right)\)

\(\Leftrightarrow(2x^3-21x^2+67x-60)/\left(x-5\right)=2x^2-11x+12\)

Answer 2

câu d sai đề rùi đúng là \((x^4+2x^3+10-25)\div\left(x^2+5\right)\)

e)\(27x^3-8=\left(3x\right)^3-2^3=\left(3x-2\right)\left(9x^2+6x+4\right)\)

\(\Leftrightarrow(27x^3-8)\div\left(6x+9x^2+4\right)=3x-2\)