Study Guide FAQ

1st

What is the test like?

Check yesterday's post!

What are the page numbers that go with the questions?

1: Pg 601
2: Pg 617-619
3 and 4: All of 11.3 and 11.4

2nd

How can I find the slope from the equations?

Both equations are in slope-intercept form or y=mx+b. The slope is m (not x, you are not ready for slopes with variables) and the y-intercept is b.  Remember that we don't write it down when we add 0 or multiply a variable by 1 because of the identity properties.

How do you tell lines are perpendicular?

The slopes are opposite reciprocals, or as a student said "Totally flipped". They are flipped over and have different signs, like 2 and -1/2 or -8/5 and 5/8. More detail here.

3rd

I still don't get how to find the slope from an equation.

Think back to or look back at chapter 3. We learned about the y-intercept form of an equation and slope then. We found out that when an equation is written like y equals some number times x plus another number that the number that was multiplied by x was the same as the slope or rate of change. Look at your equation. What number was multiplied by x? That is the slope.

How do I graph these lines?

Either make a table and plot the points or use the slope and y-intercept.

4th

Can you show us one more substitution problem?

We did one in class and here's another really broken down. I got the problem from here. I think it was number 10.

I look at both equations and think, "Which one will be easier to solve for a variable?" I decided that the first one would be easier to solve for y because y is not being multiplied by anything.

I solve for y by adding 5x to both sided. I added because -5 and +5 are inverses which means they add up to 0. I want 0x with my y. I cannot really add the 5x and 3 to get anything that makes sense so I leave them a math problem.

Take the y out of the OTHER equation and put the math problem that is the same as y from the previous step in it's place. I wrote this in blue so you can see it. Then solve using the same old rules as always. (First, I made everything addition to be sure that I could rearrange as needed and keep the signs all correct. Then I used the distributive property to deal with my parenthesis. Then I combined like terms on the same side of the equals. Then I used inverse operations to get x all alone.)

Plug 0 in for x in the other equation because x=0. Solve for y.

Your solution is (0,-3)

Does slope have to be a fraction because of rise over run?

All number are kinda secretly fractions. 3 is the same as 3/1.

How do I know which equation to start with?

It doesn't really matter. I look for a variable that isn't being multiplied by anything so I won't get fractions. Here's the problem above to the first half of the solution done by solving the first equation for x. It was more difficult, but I get the same answer.

If I plug y=-3 in the other equation, I will get x=0.

6th


7th