What is the length of the interval of solutions to the inequality 1 ( is less than or equal to) 3-4x (is less than or equal to) 9?

I presume that I just plug in numbers for x? The problem is, that all the positive numbers I've tried have made them way less than one, when its supposed to be greater than or equal to. Are negative numbers the answer?

Thanks!

1 answer

3 - 4x = 9
-4x = 6
x = -6/4 = -1.5 = highest value for x in interval of solutions.

With this, you should be able to do a similar process to find the lowest value to define "length of the interval of solutions".

I hope this helps. Thanks for asking.