Question

Which of the following is the solution for 9<=1-4x<21

Answer 1

-5 < x <=-2

Explanation:

9<=1-4x<21

Subtract 1 from each side

9 -1<=1-1-4x<21-1

8 <= -4x < 20

Divide each side by -4. That means to flip all inequalities

8/-4 >= -4x/-4 >20/-4

-2 >=x > -5

-5 < x <=-2