Day 79 – January 4

HAPPY NEW 2010!

Algebra: Chapter 9 Review

Remember! IN GRAPHING SYSTEMS OF LINEAR INEQUALITIES! For the first equation, we can use any technique we learned from Chapter 7. Usually, the slope-intercept or `x` and `y` intercepts can be used to quickly define the line. Check a simple point like (0, 0) to see if that part of the ½ plane is true. If so, then shade that area.

Do the same for the other inequality and shade the appropriate ½ plane. The IMPORTANT PART is WHERE THE 2 INEQUALITIES OVERLAP THEIR SHADING, IS THE SOLUTION TO BOTH INEQUALITIES.

Have your notes organized for TOMORROW’s CHAPTER 9 TEST!

¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦ ¤ ¦¦

Algebra 1a: Chapter 7, Lesson 3, page 313

Linear Equations and their Graphs

Linear equation have to have variables with a power of 1, NO mixed variable products and NO variables in an equation in the denominator. The easiest way to plot or graph an equation is to use the x-intercept and y-intercept.

  • The x-intercept of a line is the x-coordinate of the point where the line intercepts the x-axis. To do this, all we have to do is set `y=0` and solve for `x`.
  • The y-intercept of a line is the y-coordinate of the point where the line intercepts the y-axis. To do this, set `x=0` and solve for `y`

The standard form of a linear equation in 2 variables is `Ax + By = C`, where A, B and C are constants.

For horizontal lines, the graph of `y = b` is the x-axis or a line parallel to the x-axis with y-intercept, `b`.

For vertical lines. the graph of `x = a` is the y-axis or a line parallel to the y-axis with x-intercept, `a`.

Two of tonight’s homework problems solved by MrE are here! Just click it.


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