An elevator starts at the 6th floor. it goes up 7 floors twice, and then it goes
down 10 floors. a second elevator starts on the 20th floor. it goes down
5 floors 3 times, and then it goes up 12 floors. which elevator ends on a
higher floor? explain how you know.

Well let's see what floor each one lands on and figure out which one is higher.

Something to note:

down = subtracting

up = adding

if something says it's doing something more than once, add it the number of times it's doing that thing. (You can also multiply it by that number but the adding way is a bit easier to understand and explain)

Elevator 1:

6 + 7 + 7 - 10 = 10

Elevator 2:

20 - 5 - 5 - 5 + 12 = 17

Elevator 2 ends on a higher floor (reasoning above)

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: