Math 11 homework for 8-30

We all need to make an adjustment to the Springboard textbook.  In conventional textbooks, the homework problems are found gathered together on one or two pages after a section.  In our Springboard book, homework problems are not found in a separate section.  Homework problems can be assigned from the activity items in the text.  It is important that you write down both the page and item numbers of homework assignments, and that you not get the two confused.

Homework for 8-30:  page 6, items 11 and 12.

Notes on the previous homework that was due today 8-29, page 5, items 6 through 10:

6.  -100 is the slope.   1360 is the y-intercept.

7a.  This item is about the expense of meals.  You need the information from pages 3 and 4 where you found that having a meal means your available money is reduced by $40.

Yesterday we wrote        D(t) = 1360 -100(t) when we talked about tickets.
Today's equation has the same y-intercept but a different slope, a different rate at which money leaves.
Today for 7a we write    D(m) = 1360 -40(m)

7b.  Be careful to see that the horizontal axis is marked in five-meal increments, so the marks from L to R go 0, 5, 10, 15, 20, and so forth.  The graph goes downhill and it drops $40 for each meal, which means it drops $200 for every five meals.

7b. IS A GOOD CANDIDATE FOR A HOMEWORK QUIZ.

8.  Today's D(m) is a ___________ function.  Hint:  what is the shape of the graph?

9.  What is the rate of change for D(m)?  (Be sure to write the units)

A rate of change is a ratio, so it's some units over some other units, or some units per some other units, or some units divided by some other units.    "Per" is a preposition which means "divided by".

In our example, the rate of change is -40 dollars per meal, or ($-40) / meal.