M = (a + b + c)³ - a³ - b³ - c³

= (a + b)³ + c³ + 3(a + b)²c + 3(a + b)c² - a³ - b³ - c³

= a³ + b³ + c³ + 3a²b + 3ab² + 3(a + b)c(a + b + c) - a³ - b³ - c³

= 3ab (a + b) + 3c(a + b)(a + b + c)

= 3(a + b)[ab + c(a + b + c)]

= 3(a + b)(ab + bc + ac + c²)

= 3(a + b)[b(a + c) + c(a + c)]

= 3(a + b)(b + c)(c + a)

N = a³ + b³ + c³ - 3abc

= (a + b)³ + c³ - 3ab(a + b) - 3abc

= (a + b + c)³ - 3(a + b)c(a + b + c) - 3ab(a + b + c)

= (a + b + c)[(a + b + c)² - 3(a + b)c - 3ab]

= (a + b + c)(a² + b² + c² + 2ab + 2bc + 2ca - 2ac - 3bc - 3ab)

= (a + b + c)(a² + b² + c² - ab - bc - ca)

\(1,\\ 1,=15\left(x+y\right)\\ 2,=4\left(2x-3y\right)\\ 3,=x\left(y-1\right)\\ 4,=2x\left(2x-3\right)\\ 2,\\ 1,=\left(x+y\right)\left(2-5a\right)\\ 2,=\left(x-5\right)\left(a^2-3\right)\\ 3,=\left(a-b\right)\left(4x+6xy\right)=2x\left(2+3y\right)\left(a-b\right)\\ 4,=\left(x-1\right)\left(3x+5\right)\\ 3,\\ A=13\left(87+12+1\right)=13\cdot100=1300\\ B=\left(x-3\right)\left(2x+y\right)=\left(13-3\right)\left(26+4\right)=10\cdot30=300\\ 4,\\ 1,\Rightarrow\left(x-5\right)\left(x-2\right)=0\Rightarrow\left[{}\begin{matrix}x=2\\x=5\end{matrix}\right.\\ 2,\Rightarrow\left(x-7\right)\left(x+2\right)=0\Rightarrow\left[{}\begin{matrix}x=7\\x=-2\end{matrix}\right.\\ 3,\Rightarrow\left(3x-1\right)\left(x-4\right)=0\Rightarrow\left[{}\begin{matrix}x=\dfrac{1}{3}\\x=4\end{matrix}\right.\\ 4,\Rightarrow\left(2x+3\right)\left(2x-1\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=-\dfrac{3}{2}\\x=\dfrac{1}{2}\end{matrix}\right.\)

Cưu là mình vs (x^2+x)^2-2(x^2+x)-15

\(=\left(x-5\right)\left(x^{^2}+1\right)\)

\(x^2\left(x-5\right)+x-5=x^2\left(x-5\right)+\left(x-5\right)=\left(x-5\right)\left(x^2+1\right)\)

\(1,\\ a,=4\left(x-2\right)^2+y\left(x-2\right)=\left(4x-8+y\right)\left(x-2\right)\\ b,=3a^2\left(x-y\right)+ab\left(x-y\right)=a\left(3a+b\right)\left(x-y\right)\\ 2,\\ a,=\left(x-y\right)\left[x\left(x-y\right)^2-y-y^2\right]\\ =\left(x-y\right)\left(x^3-2x^2y+xy^2-y-y^2\right)\\ b,=2ax^2\left(x+3\right)+6a\left(x+3\right)\\ =2a\left(x^2+3\right)\left(x+3\right)\\ 3,\\ a,=xy\left(x-y\right)-3\left(x-y\right)=\left(xy-3\right)\left(x-y\right)\\ b,Sửa:3ax^2+3bx^2+ax+bx+5a+5b\\ =3x^2\left(a+b\right)+x\left(a+b\right)+5\left(a+b\right)\\ =\left(3x^2+x+5\right)\left(a+b\right)\\ 4,\\ A=\left(b+3\right)\left(a-b\right)\\ A=\left(1997+3\right)\left(2003-1997\right)=2000\cdot6=12000\\ 5,\\ a,\Leftrightarrow\left(x-2017\right)\left(8x-2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=2017\\x=\dfrac{1}{4}\end{matrix}\right.\\ b,\Leftrightarrow\left(x-1\right)\left(x^2-16\right)=0\Leftrightarrow\left[{}\begin{matrix}x=1\\x=4\\x=-4\end{matrix}\right.\)

x(x + 2) + x(x - 5) - 5(x + 2)

= [x(x + 2) - 5(x + 2)] + x(x - 5)

= (x - 5)(x + 2) + x(x - 5)

= (x - 5)(x + 2 + x)

= (x - 5)(2x + 2)

= 2(x - 5)(x + 1)

Câu 4:

D=(x+1)(x+3)(x+5)(x+7)+15

\(=\left(x^2+8x+7\right)\left(x^2+8x+15\right)+15\)

\(=\left(x^2+8x\right)^2+22\left(x^2+8x\right)+105+15\)

\(=\left(x^2+8x\right)^2+22\left(x^2+8x\right)+120\)

\(=\left(x^2+8x+12\right)\left(x^2+8x+10\right)\)

\(=\left(x+2\right)\left(x+6\right)x^2+8x+10\)

Câu 2:

b: \(4x^2-12x+9\)

\(=\left(2x\right)^2-2\cdot2x\cdot3+3^2\)

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

Câu 1:

a: \(4x^2-9y^2=\left(2x\right)^2-\left(3y\right)^2=\left(2x-3y\right)\left(2x+3y\right)\)

b: \(\left(3x+y\right)^3=\left(3x\right)^3+3\cdot\left(3x\right)^2\cdot y+3\cdot3x\cdot y^2+y^3\)

\(=27x^3+27x^2y+9xy^2+y^3\)

Biểu thức này không phân tích được thành nhân tử nữa bạn nhé.

Phân tích đa thức sau thành nhân tử:( x-5 )\(^2\)- 5 + x

Bài làm:

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

= ( x - 5 )\(^2\)+ ( x - 5 )                                         Chỗ này có thể phân tích thành ( x - 5 ) ( x - 5 ) + ( x - 5 ) nha

= ( x - 5 ) \([\)( x - 5 ) + 1 \(]\)

= ( x- 5 ) ( x - 5 + 1 )

* Chúc bạn học tốt ^^

# Linh

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