1、解下列不等式组(1)﹛8x+5>9x+6,① (2)﹛2x+3≤5,①﹛2x-1<7 ② ﹛3x-2≥4 ②2、求不等式5(x-2)≤28+2x的正整数解

问题描述:

1、解下列不等式组
(1)﹛8x+5>9x+6,① (2)﹛2x+3≤5,①
﹛2x-1<7 ② ﹛3x-2≥4 ②
2、求不等式5(x-2)≤28+2x的正整数解

  1. 移项,得到x<-1和x<4,最后答案 x<-1

  2. x<=1和x>=2,无解

  3. 5x-10<=28+2x,3x<=38,x<=38/3,所以答案有 1,2,3,4,5,6,7,8,9,10,11,12

(1) x(2) 无解
2 1,2,3,4,5,6,7,8,9,10,11,12

(1)x2 1,2,3,4,5,6,7,8,9,10,11,12,13,

1)x2、 1,2,3,4,5,6,7,8,9,10,11,12,

(1):由①:x<-1由②:x<4∴x<-1(同小取小)(2):由①:x≤1由②:x≥2∴x无解(3):5(x-2)≤28+2x∴5x-10≤28+2x∴3x≤38x≤38/3,满足正整数的x只要分母是3的倍数且≤38就可分母为3,6,9,12,15,18,21,24,27,...