Section 6.3- Solving Systems of Equations Using Elimination

Essential Question: How and why are systems of equations useful in modeling real world problems?

Do Now:

Weight of Apple: Weight of Orange:

Solving Systems Using Elimination

There is ________________________________ to __________ a system of equations

Should ________________ equations so they are both in _________________________________

Look to see if ____________________ or ____________________ the equations together will _____________________ a variable

When ______________________ the equations together, _______________________________________________

When _______________________ the equations, _____________________ ________________________________________

Example 1: Solving a System by Adding Equations

What is the solution of the system? Use elimination. Be sure to write your solution as a coordinate.

a.

b.

c.

Example 2: Solving a System by Subtracting Equations

Solve each system using elimination. Be sure to write your final answer as a coordinate.

a.

b.

c.

Example 3: Solving a System by Multiplying One Equation

What is the solution of the system? Use elimination.

a.

b.

Example 4: Solving a System by Multiplying Both Equations

What is a solution of the system? Use elimination.

a.

b.

Example 5: Finding the Number of Solutions

How many solutions does the system have? Use elimination to determine.

a.

b.

Example 6: Solving a Word Problem Using Elimination

The theater club sells a total of 101 tickets to its first play. A student ticket costs $1. An adult ticket costs $2.50. Total ticket sales are $164. How many student tickets were sold?

Summary of Solving Systems by Elimination

Group Work:

Solve each system by elimination.

1.

2.

3.

4.

HW:

p. 382-383 #8-11, 16-26 evens, 32, 33, 39