Algebra: Chapter 7-4, p 318
Slope of a Line
The slope of a line is the tilt or slant. The slope is defined as the letter `m` and `m= (rise)/(run)`, where the `rise` is the change in the y-coordinate and the `run` is the change in the x-cordinate. This definition works great when you have 2 points on graph paper. You can just count the squares for the rise and the run. It doesn’t matter too, which point you start with.
Remember, slope is positive if the line is going from lower left to upper right. The slope is negative if its coming from upper left to lower right.
A slope of 0 is a horizontal line and a line with NO SLOPE is a vertical line.
Another definition of slope, given 2 point and NO GRAPH PAPER is:
- `m=(y2−y1)/(x2−x1)`, where `(x1, y1)` and `(x2,y2)` are 2 points on the line.
Purplemath has this link as well.
Math 8, Chapter 5-3
Adding and Subtracting Decimals
Remember to line up the decimals when adding or subtracting decimals! Decimals follow the same rules as other rational numbers:
- Commutative Property: `-8.1 +9.6 = 9.6 +(-8.1)`
- Associative Property:` (-3.5 +5.2) +3.1 = -3.5 +(5.2 +3.1)`
- Identity Property: `0 + 5.2 = -5.2`
- Inverse Property: `15.8+(-15.8)=0`