May 4, 2011

Substitution Method
Works really well if one of the variable is already solved. (For example, you know what y equals)

The values of x and y were found using the Substitution Method
You should write your answer as an ordered pair  (8,11)

More examples using the Substitution Method.
Don't forget to write answers as ordered pairs.

Solving Systems Using Eliminaton Method
x and y are generally on the same side.  We are going to add the two equations together.

Inequalities -

Hint: read from the variable.  For example: x > 3 is read "x is greater than 3"  3 < x "x is greater than 3"
Solve inequalities like you would equations.

Determine whether each number is a solution of the given inequality.

Graph each inequality

I made a mistake on #15.  If the swimmer is greater than 23, he/she doesn't qualify.
The inequality should be x< 23.  He/she needs to be less than 23.

Solving Inequalities
If you multiply or divide by a negative number, you MUST flip/reverse the inequality sign.

Linear Inequality


The easiest test point is (0,0)  If the line passes through the origin, you can't use (0,0) the test point can't be on the line.
If the inequality is greater than or equal to OR less than or equal to the line is solid.
If the inequality is greater than or less than the line is dashed

Is the statement true or false:

• y < 3x + 2 - test point (0,0).....0 < 3(0) + 2 = 0 < 2......this statement is true.

Graphing linear inequalities

In linear inequalities, we are looking at a region.

Homework:
Worksheets: All Mixed Up and All Mixed Up Again