Question

21 is less than or equal to -3(x-4) is less than 18

Answer 1

-3 ≤ x <-2

Explanation:

First, you should set up the equation to solve it, which is,

21 ≤ -3(x-4)<18

Then you should simplify the equation to,

21 ≤ -3x+12<18

Then subtract 12 from both sides.

9 ≤ -3x<6

Lastly, divide -3 from both sides.

-3 ≤ x<-2