1:2X²+X-3=(2x+3)(x-1)
2:-6a²+7a+5=(-2a-1)(3a-5)
3:(X²-X)²-(X²-X)-2=[(X²-X)-2][(X²-X)+1]=(X²-X-2)(X²-X+1)=(x-2)(x+1)(X²-X+1)
4:X的三次方+3X-4=X的三次方-X²+X²+3X-4=X²(x-1)+(x-1)(x+4)=(x-1)(X²+x+4)
5:X的三次方-X²+X-1=X²(x-1)+(x-1)=(x-1)(X²+1)
6::X²+4(XY-1)+4Y²=:X²+4XY+4Y²-4=(x+2y)²-4=(x+2y+2)(x+2y-2)
7:已知X的三次方-2X²Y-XY²+2Y的三次方=0 X>Y>0 化简XZ-2YZ+1
X的三次方-2X²Y-XY²+2Y的三次方=X²(x-2y)-y(x-2y)=(x-2y)(X²-y)=0 x=2y X²=y(X>Y>0 X²>y 不合题意,舍去) 故x=2y XZ-2YZ+1=2YZ-2YZ+1=1