Phân tích các đa thức sau thành nhân tử ( phương pháp đặt thừa số chung )
1) -4a - 8b - 12c
2) 9ab - 18a + 9
3) -ax2 - ax - a
4) -2a2 b - 4ab2 - 6ab
5) mxy - m2 x + my
6) 12x3 y - 6xy + 3x
7) mx( a + b ) - m( a + b )
8) xm + 2 - xm + 1
9) 5x2 y( x - 7 ) - 5xy( 7 - x )
Các bạn giải nhanh cho mình đi. Mình đang cần gấp lắm
1) \(-4a-8b-12c=-4\cdot\left(a+2b+3c\right)\)
2) \(9ab-18a+9=9\cdot\left(ab-2a+1\right)\)
3) \(-ax^2-ax-a=-a\left(x^2+x+1\right)\)
4) \(-2a^2b-4ab^2-6ab=-2ab\left(a+2b+3\right)\)
5) \(mxy-m^2x+my=m\left(xy-mx+y\right)\)
6) \(12x^3y-6xy+3x=3x\left(4x^2y-2y+1\right)\)
7) \(mx\left(a+b\right)-m\left(a+b\right)=m\left(a+b\right)\left(x-1\right)\)
8) \(x^{m+2}-x^{m+1}=x^{m+1}\left(x-1\right)\)
9) \(5x^2y\left(x-7\right)-5xy\left(7-x\right)=5x^2y\left(x-7\right)+5xy\left(x-7\right)=5xy\left(x-7\right)\left(x+1\right)\)
1) -4a - 8b - 12c = -4 ( a + 2b + 3c)
2) 9ab - 18a + 9 = 9 ( ab - a +1 )
3) -ax2 - ax - a = -a ( x2 + x + 1)
4) - 2a2b - 4ab2 - 6ab = -2ab ( a + 2b + 3 )
5)mxy - m2x + my = m ( xy - mx + y )
6)12x3y - 6xy + 3x = 3x ( 4x2y - 2y + 1 )
7) mx ( a+ b) - m (a+b) = (a+b) ( mx-m ) = m ( a+b)(x-1)
8) xm+2 - xm+1 = xm + 1 (x -1 )
9) 5x2y ( x-7 ) - 5xy ( 7 -x )
= 5x2y ( x -7 ) + 5xy ( x-7 )
= 5xy ( x +1 ) (x-7)