Question

解不等式组①3x-2(9-x)>3(7+2x)-(11-6x). ②2(3x-1)-3(4x+5)≤x-4(x-7）

Answer 1

解：①3x-2(9-x)>3(7+2x)-(11-6x)
由原式可得 3x-18+2x>21+6x-11+6x即
5x-18>10+12x
-28>7x
解得x＜－4
②2(3x-1)-3(4x+5)≤x-4(x-7)
由原式展开得 6x-2-12x-15≤x-4x+28、即
-6x-17≤-3x+28
-45≤3x
解得 x≥-15
所以 、不等式组的解集为{x│-15≤x＜-4﹜

Answer 2

1.             3x-18+2x>21+6x-11+6x

                    5x-18>12x+10

                        -7x>28

                                x<-4

2.                 6x-2-12x-15≤x-4x+28

                           -6x-17  ≤-3x+28

                                -3x  ≤45

                                   x ≥-15

    交集：       -15≤x<-4