(X-X/3)^2-10X+21>0怎么解
问题描述:
(X-X/3)^2-10X+21>0怎么解
答
x-x/3=2x/3
(2X/3)^2=4X^2/9
都乘以9得 4X^2-90X+189>0
...下面你因该会解了