x2-9x+ 18大于等于0怎么解

2025-12-14 06:37:38
推荐回答(1个)
回答1:

x2-9x+ 18>0
x2-2*9/2x+ 81/4+18>81/4
(x-9/2)^2>81/4-18
(x-9/2)^2>9/4
x-9/2>3/2或x-9/2<-3/2
x>6或x<3