20 less than or equal to 2x -20 less than or equal to 30

Answer = 0 ≤ x ≤ 25

Explanation:  

Break the word equation into two for better understanding  

-20 less than or equal to 2x -20 >>>> -20 ≤ 2x -20

2x -20 less than or equal to 30 >>>> 2x -20 ≤ 30

Keeping in view the question we deduce the equation  

-20 ≤ 2x -20 ≤ 30

Solve and simplify the above equation accordingly, by breaking down the equation

-20 ≤ 2x -20      and   2x -20 ≤ 30

-20+20 ≤ 2x      and   2x ≤ 30 +20

    0 ≤ x (0/2)    and     x ≤ 25 (50/2)

So,    0 ≤ x ≤ 25

i do not know this sorry : (