Ta có: \(-8x^2+23x+3\)

\(=\left(-8x^2+24x\right)-\left(x-3\right)\)

\(=-8x\left(x-3\right)-\left(x-3\right)\)

\(=\left(-8x-1\right)\left(x-3\right)\)

\(=\left(3-x\right)\left(8x+1\right)\)

\(-8x^2+23x+3\)

\(=-\left(8x^2-23x-3\right)\)

\(=-\left(8x^2-24x+x-3\right)\)

\(=-\left[8x\left(x-3\right)+\left(x-3\right)\right]\)

\(=-\left(8x+1\right)\left(x-3\right)\)

-8x² + 23x + 3

= -8x² - x + 24x + 3

= -x( 8x + 1 ) + 3( 8x + 1 )

= ( 8x + 1 )( 3 - x )

đầu cắt moi đêi

ai ko trả lời đc thì cho mình xin cái địa chỉ nhà bạn với. Mình không làm gì đâu mình chỉ nói:"vàng bạc mày nhiều nhở....hoặc mình cùng nắm chim nhau vào chai rượu này..."

lạy chúa tôi lớp 6 đã học phân tích nhân tử rồi :D

a) 35x² + 36x - 20

= 35x² + 50x - 14x - 20

= 5x( 7x + 10 ) - 2( 7x + 10 )

= ( 7x + 10 )( 5x - 2 )

b) 3x⁴ - 8x² - 35

= 3x⁴ - 15x² + 7x² - 35

= 3x²( x² - 5 ) + 7( x² - 5 )

= ( x² - 5 )( 3x² + 7 )

c) 8x² - 23x - 3

= 8x² - 24x + x - 3

= 8x( x - 3 ) + ( x - 3 )

= ( x - 3 )( 8x + 1 )

x⁴ - 4x³ - 8x² + 8x 

 = x(x³ - 4x² - 8x + 8) 

= x[x³ + 8 - 4x(x + 2)] 

= x[(x + 2)(x² - 2x + 4) - 4x(x + 2)] 

= x(x + 2)(x² - 6x + 4)

= x(x + 2)(x² - 6x + 9 - 5) 

 = \(x\left(x+2\right)\left[\left(x-3\right)^2-5\right]=x\left(x+2\right)\left(x-3+\sqrt{5}\right)\left(x-3-\sqrt{5}\right)\)

\(x^4-4x^3-8x^2+8x\)

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

\(=x\left(x^3-6x^2+2x^2+4x-12x+8\right)\)

\(=x\left[\left(x^3-6x^2+4x\right)+\left(2x^2-12x+8\right)\right]\)

\(=x\left[x\left(x^2-6x+4\right)+2\left(x^2-6x+4\right)\right]\)

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

\(=x\left[\left(x-3\right)^2-\left(\sqrt{5}\right)^2\right]\left(x+2\right)\)

\(=x\left(x-3-\sqrt{5}\right)\left(x-3+\sqrt{5}\right)\left(x+2\right)\)

=x³+3x²+3x+1+27x³

=(x+1)³ +(3x)³

=(x+1+3x) ( (x+1)²-(x+1).3x+(3x)²)

=(4x+1) (x²+2x+1-3x²-3x+9x²)

=(4x+1)(7x²-x+1)

Phương trình 18 x 2 + 23x + 5 = 0 có a – b + c = 18 – 23 + 5 = 0  nên phương trình có hai nghiệm phân biệt là x 1 = − 1 ;   x 2 = − 5 18 . Khi đó A = 18 (x + 1) x + 5 18

Đáp án: A

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

= \(x^4-2x^3-6x^3+12x^2-x^2+2x+6x-12\)

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

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

= \(\left(x-2\right)\left(x^2\left(x-6\right)-\left(x-6\right)\right)\)

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

x⁴ - 8x³ + 11x² + 8x - 12

= (x³ - 7x² + 4x + 12)(x - 1)

= (x³ - 8x + 12)(x + 1)(x - 1)

= (x - 6)(x - 2)(x + 1)(x - 1)

Trả lời:

2x³ - 8x² - 8x 

= 2x ( x² - 4x - 4 )