September 24 th, 2015 Questions? In past years we studied systems of linear equations. We learned...

Warm Up #1 September 24

Systems of EquationsSeptember 24th, 2015

Test 1Average: 86.5-89%Progress ReportsQuestions?

In past years we studied systems of linear equations.

We learned three different methods to solve them.

Elimination, Substitution and Graphing

Graphing Method

To solve is to find the intersections of the graph.

Put each in slope intercept form and graph

Calculator Notes

1. Type equation 1 = y1, equation 2 = y2

2. Push 2ndTRACE5, move cursor to the left intersection push ENTER 3 times.

3. Push 2ndTRACE5, move cursor to the right intersection push ENTER 3 times.

Example 1-ONE Solution

53

1042

yx

yx

Example 2-NO solutions

723

1046

yx

yx

Example 3-INFINITE Solutions

264

132

yx

yx

Substitution Method

If we know that y = y. Then you can set both of the right hand sides of the equations equal.

Example 1-ONE Solution

53

1042

yx

yx

Example 2-NO solutions

723

1046

yx

yx

Example 3-INFINITE Solutions

264

132

yx

yx

Elimination Method

We want to eliminate one of the variables. If the equation is not set up so a variable will cancel, multiply each side by a number that will be able to cancel

Example 1-ONE Solution

53

1042

yx

yx

Example 2-NO solutions

723

1046

yx

yx

Example 3-INFINITE Solutions

264

132

yx

yx

Solve on your own!

Word Problems

Graphs & Solutions

Homework

Pg. 158 #1-4 Pg. 159 #1-3,5 Pg. 160 #1-2