Algebra: Chapter 7-1 and 7-2, p 304 and 309
Chapter 7-1 Coordinates
Coordinates are defined as (x, y) where the x-axis runs left to right and the y-axis runs up and down. The origin is where the points (0,0) exists. A fancy word for the x-axis is the abscissa and the y-axis is the ordinate. There are 4 quadrants:
- I – both x and y axis have positive value
- II- x axis is negative and y axis is positive
- III – both x and y axis have negative values
- IV – x axis has positive value, while the y axis has negative value
By substituting a coordinate pair (x, y) into a linear equation, we can determine if the ordered pair is a solution to the linear equation. Just substitute for x the value of the first of the ordered pair, and substitute for y, the second value of the ordered pair. If the evauation is true, then the ordered pair fits on the line.
Chapter 7-2 Graphing Equations
We can graph an equation, by building a T-chart of values for both x and y. You can choose any values for x and y when making your T-chart. I like to use values like 0, 1, and 2. Make them easy and try to pick AT LEAST 3 points when graphing and equation. YOU MUST USE A RULER WHEN CONNECTING THE DOTS TOO!
Sometimes, it can be easier when building the T-chart to “solve for y” first, this just cuts down on the workload. Solving for y means isolating the y variable to one side of the equation and keeping the constants and ALL other variables on the other side.
Math 8: Chapter 5-1
Rational Numbers
Whole Numbers: 0, 1, 2, 3 …
Integers: -2, -1, 0, 1, 2 …
Rational Numbers: Any number that can be expressed as a ratio a/b.
A terminating decimal is a decimal that just ends, like 2.45. A repeating decimal goes on forever, like 3.33333333 or 3 and 1/3. Remember, the bar in a repeating decimal denotes the numbers that repeat!