已知A=x3-5x2,B=x2-11x+6,求A-2B的值.

已知A=x3-5x2,B=x2-11x+6,求A-2B的值.

∵A=x3-5x2,B=x2-11x+6,∴A-2B=(x3-5x2)-2(x2-11x+6)=x3-5x2-2x2+22x-12=x3-7x2+22x-12.