Graphing Slope-Intercept Equations

Site: Saylor Academy
Course: GKT101: General Knowledge for Teachers – Math
Book: Graphing Slope-Intercept Equations
Printed by: Guest user
Date: Sunday, May 19, 2024, 7:08 PM

Description

As you have seen from examples, you can write linear equations in different ways. There are three main forms of linear equations: slope-intercept, point-slope, and standard. This lecture series introduces the point-slope form. Watch the videos and complete the interactive exercises. This lecture series focuses on graphing linear equations when they are given in slope-intercept form.

Graph from slope-intercept form - Questions

1. Graph y=-x-6.


2. Graph y=\frac{2}{3} x-4


3.Graph y=-3 x+7.


4. Graph y=\frac{6}{5} x+1.

Answers

1. The equation is in slope-intercept form: y=m \cdot x+b. In this form, m gives us the slope of the line and b gives us its y-intercept.

So y=-x-6 has a slope of -1 and a y-intercept at  (0,-6).

We need two points. We already have the y-intercept (0,-6).

We can find a second point by reasoning about the slope. A slope of -1 means when the x-value increases by 1, the y-value decreases by 1.

(0+1,-6-1)=(1,-7)


Now we can graph the equation.



2. The equation is in slope-intercept form: y=m \cdot x+b. In this form, m gives us the slope of the line and b gives us its y-intercept.

So y=\frac{2}{3} x-4 has a slope of \frac {2}{3} and a y-intercept of (0. -4).

We need two points. We already have the y-intercept (0,-4).

We can find a second point by reasoning about the slope. A slope of \frac{2}{3} means that when the x-value increases by 3, the y-value increases by 2.

(0+3,-4+2)=(3,-2)

Now we can graph the equation.


3. The equation is in slope-intercept form: y=m \cdot x+b. In this form, m gives us the slope of the line and b gives us its y-intercept.

So y = -3x+7 has a slope of -3 and a y-intercept at (0,7).

We need two points. We already have the y-intercept (0,7).

We can find a second point by reasoning about the slope. A slope of -3 means that when the x-value increases by 1, the y-value decreases by 3.

(0+1,7-3)=(1,4)

Now we can graph the equation.


4. The equation is in slope-intercept form: y=m \cdot x+b. In this form, m gives us the slope of the line and b gives us its y-intercept.

So y=\frac{6}{5} x+1 has a slope of \frac{6}{5} and a y-intercept at (1, 0).

We need two points. We already have the y-intercept (0,1).

We can find a second point by reasoning about the slope. A slope of \frac {6}{5} means that when the x-value increases by 5, the y-value increases by 6.

(0+5,1+6)=(5,7)

Now we can graph the equation.