l=0.5t+9. If this is true, what is the rate of growth of Liza's hair in inches per month?

Question

it's very hard on the computer brake it down for  me.

Answer 1

Looks like this problem is meant to teach how to balance units of measurement.

I’m assuming that   
               l = length of Liza’s hair
               t = time in number of months of growth

Now, not written is that 9 inches in the initial length of Liza’s hair (length at t=0) and that 0.5 inches per month is the rate of growth of Liza’s hair  (sounds reasonable to me).

Note that when you multiply 0,5 inches/month * t months,   the months cancel out and you are left with inches, which you can add to 9 inches to get a current length in inches.

This is why such math problems should always state the units.  Some problems are made harder by stating the length in inches and then asking for the answer in feet !