1. Quick Graphs Using Intercepts
4.3
Quick Graphs Using Intercepts

2. Learning Goal #1 for Focus 4 (HS.A-CED.A.2, HS.REI.ID.10 & 12, HS.F-IF.B.6, HS.F-IF.C.7, HS.F-LE.A.2): The student will understand that linear relationships can be described using multiple representations. 4 3 2 1
In addition to level 3.0 and above and beyond what was taught in class,  the student may:
· Make connection with other concepts in math
· Make connection with other content areas.
The student will understand that linear relationships can be described using multiple representations.
- Represent and solve equations and inequalities graphically.
- Write equations in slope-intercept form, point-slope form, and standard form.
- Graph linear equations and inequalities in two variables.
- Find x- and y-intercepts.
The student will be able to:
- Calculate slope
- Determine if a point is a solution to an equation.
- Graph an equation using a table and slope-intercept form.
With help from the
teacher, the student has
partial success with calculating slope, writing an equation in slope-intercept form, and graphing an equation.
Even with help, the student has no success understanding the concept of a linear relationships.

3. The Quick Way to Graph an Equation:
Find where the line crosses the x and y axis and connect the two points.

4. Ordered pair results, x value and y=0 (x,0)
X-intercept: the x-intercept of a line is the value for x when y=0
So, set y=0 in the equation and solve for x.
Ax+By=C
Ax+B(0)=C
Ax=C
Ordered pair results, x value and y=0 (x,0)

5. Gives the y value, ordered pair (0,y)
Y-intercept: the y-intercept of a line is the value for y when x=0
So, set x=0 in the equation and solve for y.
Ax+By=C
A(0)+By=C
By=C
Gives the y value, ordered pair (0,y)

6. Now, graph two points and connect a line between them.
DO NOT PUT THE X VALUE AND Y VALUE TOGETHER AS AN ORDERED PAIR!!!! YOU HAVE TWO DIFFERENT POINTS TO PLOT!!
Now, graph two points and connect a line between them.

7. Find the x-intercept & y-intercept and graph 2x+3y=12
When y=0
When x=0
2x+3y=12
2x+3y=12
2(0)+3y=12
2x+3(0)=12
3y=12
2x=12
y=4
x=6
(6, 0)
(0, 4)

8. Graph 6
(0, 4)
(6, 0) 5 4 3 2 1

9. Find the x & y intercepts and graph -4x+6y=18
When y=0
When x=0
-4x+6y=18
-4x+6y=18
-4(0)+6y=18
-4x+6(0)=18
6y=18
-4x=18
y=3
x=-4 ½
(-4 ½ , 0)
(0, 3)

10. Graph 6
(0, 3)
(-4 ½ , 0) 5 4 3 2 1