因式分解:12x^2-5x-2;2x^2+4xy+2y^2-8z^2 解方程:{x+y^2=6,y=x};x-12+根号x=0;x^2 +3x+根号(x^2+3x)=6

问题描述:

因式分解:12x^2-5x-2;2x^2+4xy+2y^2-8z^2 解方程:{x+y^2=6,y=x};x-12+根号x=0;x^2 +3x+根号(x^2+3x)=6

12x^2-5x-2=(3x^2-2)*(4x^2+1)2x^2+4xy+2y^2-8z^2=2(x+y+2z)*(x+y-2z) 解方程:{x+y^2=6,y=x}; y=x则x+x^2-6=0(x+3)*(x-2)=0x=-3或x=2x-12+根号x=0;x=(12-x)^2x=144+x^2-24xx^2-25x+144=0(x-16)*(x-9)=0x=16或x=...