x^2一3x+2=0用配方法。解:ⅹ^2一3x=一2x^2一3x+9/4=一2+9/4(ⅹ一3/2)^2=1/4x一3/2=±1/2∴x1=2,x2=1。
解:x^2-3x+2=0x^2-3x+(3/2)^2-9/4+2=0x^2-3x+(3/2)^2-1/4=0(x-3/2)^2=1/4x-3/2=±1/2x=2或x=1
x²-3x+2=0解:(x-1)(x-2)=0解得 x1=1;x2=2
(x-1)乘以( x-2)