因式分解的公式是什么
x?-2x?+x
解:原式=x(x?-2x+1)
=x(x-1)?
(1-a?)(1-b?)-4ab
解:原式=1-a?-b?+a?b?-4ab
=(1-ab)?-(a+b)?
=(1-ab+a+b)(1-ab-a-b)
(x?+5x+9)(x?-3x+7)-3(4x+1)?
解:设t=[(x?+5x+9)+(x?-3x+7)]/2=x?+x+8
则原式=[t+(4x+1)][t-(4x+1)]-3(4x+1)?
=t?-(4x+1)?-3(4x+1)?
=t?-4(4x?+1)?
=t?-[2(4x+1)]?
=t?-(8x+2)?
=(t+8x+2)(t-8x-2)
=(x?+9x+10)(x?-7x+6)
=(x?+9x+10)(x-1)(x-6)
2α+3α?+2α?-32
解:原式=2α?+3α?-14α+16α-32
=α(2α?+3α-14) +16(α-2)
=α(α-2)(2α+7)+16(α-2)
=(α-2)(2α?+7α+16)
2acx+4bcx+adx+2bdx+4acy+8bcy+2abdy+4bdy
解:原式=(2acx+4bcx+adx+2bdx)+(4acy+8bcy+2ady+4+bdy)
=x(2ac+4bc+ad+2bd)+2y(2ac+4bc+ad+2bd)
=(2ac+4bc+ad+2bd)(x+2y)
=[2c(a+2b)+d(a+2b)](x+2y)
=(a+2b)(2c+d)(x+2y)