(X+2)(X+3)(X-4)(X-5)=144
问题描述:
(X+2)(X+3)(X-4)(X-5)=144
答
(X+2)(X+3)(X-4)(X-5)=144左边分组:[(X+2)(X-4)][(X+3)(X-5)]=144整理得:(X^2-2X-8)(X^2-2X-15)=144换元:设X^2-2X-8=Y则原方程可化为:Y(Y-7)=144 解得Y=16或Y=-9再解X^2-2X-8=16和X^2-2X-8=-9不再赘述....