a: Sửa đề: \(27x^3-27x^2+9x-1\)

\(=\left(3x-1\right)^3\)

b: \(=\left(x-1\right)^3\)

c: \(=\left(x+\dfrac{1}{3}\right)\left(x^2-\dfrac{1}{3}x+\dfrac{1}{9}\right)\)

a) (3x-1)³ Xem lại đề câu a là -1

^b) (x-1)³

c) (1/3 + x)(1/9 -x.1/3 +x²)

d) (0,1-10x)(0,01 + x +100x²)

b: \(x^3+\dfrac{1}{27}=\left(x+\dfrac{1}{3}\right)\left(x^2-\dfrac{1}{3}x+\dfrac{1}{9}\right)\)

c: \(x^3-3x^2+3x-1=\left(x-1\right)^3\)

e: \(a^2y^2-2axby+b^2x^2\)

\(=\left(ay\right)^2-2\cdot ay\cdot bx+\left(bx\right)^2\)

\(=\left(ay-bx\right)^2\)

f: \(100-\left(3x-y\right)^2\)

\(=\left(10-3x+y\right)\left(10+3x-y\right)\)

g: \(64x^2-\left(8a+b\right)^2\)

\(=\left(8x\right)^2-\left(8a+b\right)^2\)

\(=\left(8x-8a-b\right)\left(8x+8a+b\right)\)

a) \(27x^3-27x^2+3x+1=27x^3-9x^2-18x^2+6x-3x+1\)

\(=\left(27x^3-9x^2\right)- \left(18x^2-6x\right)-\left(3x-1\right)\)

\(=9x^2\left(3x-1\right)-6x\left(3x-1\right)-\left(3x-1\right)\)

\(=\left(3x-1\right)\left(9x^2-6x-1\right)\)

b) \(x^3-3x^2+3x-1=x^3-3.x^2.2+3.x.1^2-1^3=\left(x-1\right)^3\)

c) \(\frac{1}{27}+x^3=\left(\frac{1}{3}\right)^3+x^3=\left(x+\frac{1}{3}\right)\left[\left(\frac{1}{3}\right)^2-\frac{1}{3}.x+x^2\right]=\left(x+\frac{1}{3}\right)\left(x^2-\frac{1}{3}x+\frac{1}{9}\right)\)

d) \(0,001-1000x^3=\left(\frac{1}{10}\right)^3-\left(10x\right)^3=\left(\frac{1}{10}-10x\right)\left[\left(\frac{1}{10}\right)^2+\frac{1}{10}.10x+\left(10x\right)^2\right]\)

\(=\left(\frac{1}{10}-10x\right)\left(100x^2+x+\frac{1}{100}\right)\)

Cảm ơn bạn nhìu

a, \(\left(x+2\right)^3-x\left(x^2+6x-3\right)=0\Leftrightarrow x^3+4x^2+4x+2x^2+8x+8-x^3-6x^2+3x=0\)

\(\Leftrightarrow15x+8=0\Leftrightarrow x=-\frac{8}{15}\)

b, \(\left(x+4\right)^3-x\left(x+6\right)^2=7\Leftrightarrow12x+64=0\Leftrightarrow x=-\frac{19}{4}\)làm tắt:P 

Tự làm nốt nhé 

\(a,\left(-3x+2\right)^3\)

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

\(=2^3-3.2^2.3x+3.2.9x^2-27x^3\)

\(=8-36x+54x^2-27x^3\)

\(a,\left(-3x+2\right)^3=\left(2-3x\right)^3=2^3-3.2^2.3x+3.2.9x^2-27x^3=8-36x+54x^2-27x^3\)