CAN SOMEONE PLS HELP FIND WHAT I DID WRONG Population Density

My teacher said that question 7 on my worksheet was wrong which I have provided a picture of down below with my work. I'm wondering maybe if she just messed up because I can't find what I did wrong? Please help.

the solution is 12x-6y

b: |12 – x| ≤ 0.25

step-by-step explanation:      

let x be the possible lengths in inches, of the ribbons jaime cut.

we have been given that jaime is cutting strips of ribbon for a project. he tries to cut each piece to be 12 inches long, but sometimes he cuts it too long or too short by as much as 0.25 inch.  

we can represent this information in an inequality as:

by the definition of absolute value function we will get,

upon combining our inequalities we will get,

therefore, the inequality   describes all the possible lengths (x), in inches, of the ribbons jaime cut.

step-by-step explanation:

a

step-by-step explanation: