`a^{3}+3a^{2}-6a-8`

`=a^{3}-8+3a(a-2)`

`=(a-2)(a^{2}+2a+4)+3a(a-2)`

`=(a-2)(a^{2}+2a+4+3a)`

`=(a-2)(a^{2}+5a+4)`

`=(a-2)(a+1)(a+4)`

\(a^3-8+3a\left(a-2\right)\)

\(=\left(a-2\right)\left(a^2+2a+4\right)+3a\left(a-2\right)\)

\(=\left(a-2\right)\left(a^2+2a+4\right)+3a\left(a-2\right)\)

\(=\left(a-2\right)\left(a^2+2a+4+3a\right)\)

\(=\left(a-2\right)\left(a^2+5a+4\right)\)

\(\left(a-2\right)\left(a+1\right)\left(a+4\right)\)

\(a^3+3a^2-6a-8\)

\(=\left(a-2\right)\left(a^2+2a+4\right)+3a\left(a-2\right)\)

\(=\left(a-2\right)\left(a^2+5a+4\right)\)

\(=\left(a-2\right)\left(a+1\right)\left(a+4\right)\)

a: Ta có: \(x^5-x^3+x^2-1\)

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

\(=\left(x-1\right)\cdot\left(x+1\right)^2\cdot\left(x^2-x+1\right)\)

b: Ta có: \(5x^3-45x\)

\(=5x\left(x^2-9\right)\)

\(=5x\left(x-3\right)\left(x+3\right)\)

c: Ta có: \(16x^4y^2+2xy^5\)

\(=2xy^2\left(8x^3+y^3\right)\)

\(=2xy^2\cdot\left(2x+y\right)\left(4x^2-2xy+y^2\right)\)

d: Ta có: \(a^3-8+6a^2-12a\)

\(=\left(a-2\right)\left(a^2+2a+4\right)+6a\left(a-2\right)\)

\(=\left(a-2\right)\left(a^2+8a+4\right)\)

e: Ta có: \(x^4+x^3+x+1\)

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

\(=\left(x+1\right)^2\cdot\left(x^2-x+1\right)\)

a ) \(x^3-7x-6=x^3-x-6x-6=x^3-x-6\left(x+1\right)\)

\(=x\left(x^2-1\right)-6\left(x+1\right)=\left(x+1\right)\left[x\left(x-1\right)-6\right]\)

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

\(=\left(x+1\right)\left[x\left(x+2\right)-3\left(x+2\right)\right]=\left(x+1\right)\left(x+2\right)\left(x+3\right)\)

b )

\(x^3-19x-30=\left(x^3-9x\right)-\left(10x+30\right)=x\left(x^2-9\right)-10\left(x+3\right)\)

\(=\left(x+3\right)\left(x^2-3x-10\right)=\left(x+2\right)\left(x+3\right)\left(x-5\right)\)

c )

\(a^3-6a^2+11a-6=\left(a-3\right)\left(a-2\right)\left(a-1\right).\)

`49b^{2}-a^{2}+6a-9`

`=(7b)^{2}-(a-3)^{2}`

`=(7b-a+3)(7b+a-3)`

\(49b^2-a^2+6a-9\)

\(=49b^2-\left(a-3\right)^2\)

\(=\left(7b-a+3\right)\left(7b+a-3\right)\)

4a²b² + 36a²b³ + 6ab⁴

= 2ab²(2a + 18ab + 3b²)

4a²b³ - 6a³b²

= 2a²b²(2b - 3a)

a) \(a^2+ab-7a-7b=a\left(a+b\right)-7\left(a+b\right)=\left(a+b\right)\left(a-7\right)\)

b) \(5ab+4c+20b+ac=5b\left(a+4\right)+c\left(a+4\right)=\left(a+4\right)\left(5b+c\right)\)

c) \(a^2+6a-b^2+9=\left(a+3\right)^2-b^2=\left(a+b-b\right)\left(a+3+b\right)\)

d) \(a^2-16=\left(a-4\right)\left(a+4\right)\)

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

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

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

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

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\(a^3+3a^2-6a-8\)

\(=a^3+4a^2-a^2-4a-2a-8\)

\(=\left(a^3+4a^2\right)-\left(a^2+4a\right)-\left(2a+8\right)\)

\(=a^2\left(a+4\right)-a\left(a+4\right)-2\left(a+4\right)\)

\(=\left(a+4\right)\left(a^2-a-2\right)\)

\(=\left(a+4\right)\left(a^2-2a+a-2\right)\)

\(=\left(a+4\right)\left[\left(a^2-2a\right)+\left(a-2\right)\right]\)

\(=\left(a+4\right)\left[a\left(a-2\right)+\left(a-2\right)\right]\)

\(=\left(a+4\right)\left(a-2\right)\left(a+1\right)\)

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\(2x^2-5x+2\)

\(=2x^2-4x-x+2\)

\(=\left(2x^2-4x\right)-\left(x-2\right)\)

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

\(=\left(x-2\right)\left(2x-1\right)\)

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\(x^2-2x-4y^2-4y\)

\(=\left(x^2-4y^2\right)-\left(2x-4y\right)\)

\(=\left(x-2y\right)\left(x+2y\right)-2\left(x-2y\right)\)

\(=\left(x-2y\right)\left(x+2y-2\right)\)

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\(a^2-1+4b-4b^2\)

\(=a^2-\left(1-4b+4b^2\right)\)

\(=a^2-\left(1-2b\right)^2\)

\(=\left(a-1+2b\right)\left(a+1-2b\right)\)

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\(a^4+6a^2b+9b^2-1\)

\(=\left(a^4+6a^2b+9b^2\right)-1\)

\(=\left(a^2+3b\right)^2-1\)

\(=\left(a^2+3b-1\right)\left(a^2+3b+1\right)\)

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\(2x^3+16y^3\)

\(=2\left(x^3+8y^3\right)\)

\(=2\left(x+2y\right)\left(x^2-2xy+4y^2\right)\)

Lần sau ghi đề tách riêng từng câu ra nhé em. Ghi dính chùm vậy khó nhìn lắm. Sẽ ít ai giải cho em