Algebra I Review Pt II

Algebra I Review Pt II-Linear Functions

Objective

​To write and use slope-intercept and point-slope form of linear equations

Vocabulary

​Standard Form of a Linear Equation

Example

Are there rules?

​So glad you asked :)

Example

Math Response

You try. Write the equation $$4x-8=9y-5$$ in standard form.

Type answer here

Correct Answer: 4x-9y=3

Deg^°

Rad

Vobaulary

​Slope-Intercept form of a Linear Equation

Graphing a line

​From slope-intercept form:

As long as you know two points on the line, you can graph it. The y-intercept is one of the points. Start at the origin (0, 0) and count up or down the b value from the equation. Place a point on your graph. Then use the slope ("rise over run" or change in y over change in x) to find the second point. Use a straight edge to draw the line.

Parallel, perpendicular, neither

​We compare slopes

Example

​Solve for y:

​Identify the slope of each line:

​Compare slopes: equal or opposite reciprocals

Multiple Choice

Your turn. Are the lines parallel, perpendicullar, or neither?

$$x+y=8\ and\ y=-x-1$$

• Parallel

• Perpendicular

• Neither

• Not enough information to determine

One other way to graph

Identify the x- and y-intercepts

Hint: the x-intercept happens when the y-value equals 0. The y-intercept happens when the x-value equals 0.

So we'll substitute 0 for y and then solve for x. Next we substitute 0 for x and solve for y. Using those two points, we can graph the line.

Example

Poll

How do you feel about your ability to write and graph linear equations?

Independent practice

In the time remaining, complete the remainder of the handout. Turn it in to my desk before you leave class.

Thank you so much!