### Scribe for Today!!

Hey students of pre-cal 20s. I'm sorry that my post is a little late. Well today's class started off with Mr K. telling us that all the gr.10 math students are going to be getting an old math exam. We are going to have a minimum of a week to finish, but there are some ground rules.

- Can't ask for outside help.
- Can't talk to other students about it.

Well now to start off with the main work we were doing today. The first question was:

Simple interest is proportional to (varies directly with) the amount borrowed. If the interest is $5 for $100 borrowed, what would the interest be for $325 borrowed.

-create a table of values for 4 different amounts

-graph the relation ( I don't know how to make a graph sorry)

-write an equation for the relation

-Table of values

**Amount Interest**

**100 5**

**150 7.50**

**285 14.25**

**400 20**

**0 0 <--- origin**

**-**Write an equation for the realtion

**I(a)= 1/20a**

This question is an example of a Direct Variation Relation, which means that the y-intercept is

**always**zero.

A Jet skirental company charges a fixed insurance premium plus an hourly rate. The total cost for two hours is $50 and for five hours is $110.

-sketch a graph (sorry again I'll try to firgure out for next time)

-what is the hourly rate

-how much is the insurance premium?

-write an equation for this realtion.

-what is the hourly rate

You can find this out by finding the slope.

(110-50)/(5-2)

= 60/3

=20

-how much is the insurance premium?

Find this by doing point slope form.

y-y1=m(x-x1)

y-50=20(x-2)

y-50=20x-40

y=20x+10

-write an equation for this relation.

A(h)=20h+10

This question is an example of Partial Variation Relation A.K.A Indirect Variation Relation. This means that the y-intercept is anything but zero.

Well that's all for me, and tonight's homework is Exercise #57 everything! Tomorrow's scribe is--------->stePhANIE

## 2 Comments:

Great scribe nee-cole!

One point though -- the equation for the first question. You wrote it as:

I(a)=1/20a

which could be misinterpreted as 1/(20a) -- not what you meant. Brackets can help; write it like this:

I(a)=(1/20)a

or

I(a)=a/20 (I like this one best)

ok could you kindly express your intention of criticizing the work of original man?

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