3.1
SOLVING LINEAR SYSTEMS OF EQUATIONS GRAPHICALLY
A system of two linear equations in two variables x and y consist of two equations of
the following form:
Ax + By = C
Equation 1
Dx + Ey = F
Equation 2
where the solution (x,y) satisfies both equations.
Checking Solutions of a Linear System:
3x – 2y = 2
x + 2y = 6
1.) Is (2,2) a solution of the above system of equations ?
2.) Is (0,-1) a solution of the above system of equations ?
Solving a System Graphically :
Graphically, the solution of the system of equations is the point where
the two lines intersect.
Find the solution of the following system of equations graphically:
3x – 2y = 2
x + 2y = 6
Verify this answer on your graphing
calculator using the intersect function.
Create a table of values for each equation.
3x – 2y = 2
x + 2y = 6
x
x
y
y
3.1
SOLVING LINEAR SYSTEMS OF EQUATIONS GRAPHICALLY
1.) Solve the following system of equations graphically. Verify your answer on your
graphing calculator.
2x – 2y = -8
2x + 2y = 4
Check Algebraically.
.
2.) Solve the following system of equations graphically. Verify your answer on your
graphing calculator.
3x – 2y = 6
3x – 2y = 2
3.) Solve the following system of equations graphically. Verify your answer on your
graphing calculator.
2x – 2y = -8
-2x + 2y = 8
3.1
SOLVING LINEAR SYSTEMS OF EQUATIONS GRAPHICALLY
Application :
You are checking out cell phone plans and discover that Talk Anytime Wireless charges
$50.00 per month for the first phone line and charges $20.00 per additional phone line.
Text Away Wireless charges $80.00 per month for the first phone line and $5.00 per
additional phone line. Use your graphing calculator to create the graph of a system of
equations to determine the number of additional phone lines for which it would be
cheaper to use Talk Anytime verses Text Away.