多项式与多项式相乘题目!
问题描述：
多项式与多项式相乘题目!
(X+1)(X+2)(X+3) (X-Y)平方-(X+Y)(X-Y)
(X+1)(X-2)(X-3)
答
1.(X+1)(X+2)(X+3) =(X+2-1)(X+2)(X+2+1)=(X+2)([(X+2)^2-1)=(X+2)^3-(X+2)=X^3+6X^2+12X+4-X-2=X^3+6X^2+11X+22.(X-Y)平方-(X+Y)(X-Y)=(X-Y)^2-(X^2-Y^2)=X^2-2XY+Y^2-X^2+Y^2=2Y^2-2XY3.(X+1)(X-2)(X-3)=(X-1+2)(X...