x的平方-7x-1=0因式分解-搜答案-智慧作业帮

不能分解了,别费劲了

3x-7x-6=(3x+2)(x-3)

解x²+4x+1=(x²+4x+4)-3=(x+2)²-(√3)²=(x+2-√3)(x+2+√3)

1-4X平方因式分解.

1-4x²=(1-2x)(1+2x)

原代數式(x+3)-25(x-1)=x+6x+9-25x+50x-25=-8(3x-7x+2)=-8(x-2)(3x-1)

(x-1)^2-4(1-x)+4=0(x-1)^2+4(x-1)+4=0((x-1)+2)^2=0(x+1)^2=0x=-1

(1+2x)(1-2x)

3x的平方-4x=0x(3x-4)=0x1=0,x2=4/3

x²-5x-6=0?(x-6)(x+1)=0

-5x-2x平方-1=02x²+5x+1=0x²+5x/2+1/2=0x²+5x/2+1/2=(x²+5x/2+25/16)-25/16+1/2=(x+5/4)

（x+1)的平方=27/64x+1=±3√3/8x=(8-3√3)/8,x=(8+3√3)/8

x^2-7x+5=x^2-7x+49/4-29/4=(x-7/2)^2-29/4=(x-7/2-√29/2)(x-7/2+√29/2)=[x-(7+√29)/2][x-(7-√29)/2]

（X一1）＾2

x(x-3)-1

4(x+1)的平方-9=(2x+2+3)(2x+2-3)=(2x+5)(2x-1)如有帮助,请采纳.谢谢

x^2-y^2-x+3y-2=(x^2-x+1/4)-(y^2-3y+9/4)=(x-1/2)^2-(y-3/2)^2=(x-1/2-y+3/2)(x-1/2+y-3/2)=(x-y+1)(x+y-2

（a-1）(a-2)x²+x-1=0[(a-1)x-1][(a-2)x+1]=0

=(X-1)-7（x-1)+5把x-1看成一个数.利用公式法.

(x-1)(x-2)-2(2-x)^2=(x-1)(x-2)-2(x-2)^2=(x-2){(x-1)-2(x-2)}=(x-2){x-1-2x+4}=(x-2)(-x+3)=-(x-2)(x-3)

1-x²=1²-x²=(1+x)(1-x)这个主要运用平方差公式：a²-b²=(a+b)(a-b)