Solving Systems of Equations
1.  Solve the linear system:  y = -2x + 9   and   y = 3x - 4

 

a. (non-graphical approach)

1. Document #1 New , #1 Add Calculator

2.  , #3 Algebra, #2 Solve System of Linear Equations
Number of equations: 2
Variable: x,y
OK

3.  Enter the equations in the boxes.

4.
  Hit
                   



Conversion to decimal not required.

 
 

b. (graphical approach)

1. Document #1 New , #1 Add Graph

2. Graph the two equations.
Hit between entries to return to entry area.

3. , #6 Aanaylze Graph,
#4 Intersection

Scroll and lock upper and lower bounds surrounding the intersection point.

4.  Intersection cordinates appear.

5. ANSWER: (2.6, 3.8)
 

 

 

2.  Solve the linear system:  x - 2y = 14   and   x + 3y = 9

 

The graphing calculator will only accept function entries that start with "f (x) =",
( "y = " ), so we need to solve these equations for"y =".
    
1.  Enter the first equation into f1(x).

to access f2(x),

2.
  Enter the second equation into f2(x).

3.
  Adjust the Window to show the intersection point if needed.
, #4 Window/Zoom, #1 Window Settings

4.  Find intersection point.
, #6 Aanaylze Graph,
#4 Intersection

Scroll and lock upper and lower bounds surrounding the intersection point.

5.  ANSWER: (12, -1)

Graph functions:

Oops!! 

 

3.  Solve linear quadratic system:  y = x2 - 4x - 2  and   y = x - 2

 

1. Enter the first equation into f1(x).

2.  Enter the second equation into f2(2).

3.
 
If needed, adjust window so intersection points are veiwable on the screen.
, #4 Window/Zoom, #1 Window Settings

4.  Use the INTERSECTION option twice to find the two locations where the graphs intersect.
 , #6 Aanaylze Graph,
#4 Intersection

Scroll and lock upper and lower bounds surrounding the intersection point.
.

5.  Answer:  (5,3)  and  (0,-2)

                   



4.  Solve 3 x 3 linear system: 
(non-graphical approach)
2x - 3y + 7z = -21
3x + 4y - z = 17
5x - y + 2z = -2
 

1. Document #1 New , #1 Add Calculator

2. , #3 Algebra, #2 Solve System of Linear Equations
Number of equations: 3
Variable: x,y,z
OK


3.  Enter the equations in the boxes.

4.  Hit

5.  Answer:  (1, 3, -2)

                   

 

 
  There is the possibility of NO SOLUTION:
The calculator will report
"No solution found" when this occurs.

There is also the possibility of
AN INFINITE NUMBER of solutions.
The calculator will show a variable, cl, in the solution, indicating any value can be substituted into that variable.


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