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Slope is the steepness of a line.
What does the 7% mean? 7% 7% is the slope of the road. It means the road drops 7 feet vertically for every 100 feet horizontally. 7 feet 100 feet So, what is slope??? Slope is the steepness of a line.
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Slopes of Lines A line with positive slope slants upward from left to right. A line with negative slope slants downward from left to right. A line with slope of 0 is horizontal. A line with an undefined slope is vertical.
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Slope can be expressed different ways:
A line has a positive slope if it is going uphill from left to right. A line has a negative slope if it is going downhill from left to right.
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Determine the slope of the line.
Start with the lower point and count how much you rise and run to get to the other point! rise 3 = = run 6 6 3 Notice the slope is positive AND the line increases!
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Determine the slope of the line.
-1 Find points on the graph. Use two of them and apply rise over run. 2 The line is decreasing (slope is negative).
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Writing Linear Equations
Linear Equation – an equation whose graph is a line. Examples: Y-Intercept the y-coordinate of the point where a line crosses the y- axis.
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Slope Intercept Form of a Linear Equation
y = mx + b slope y-intercept What are the slope and y-intercept of y = 3x – 5 ? the slope is 3, and the y-intercept is -5 What are the slope and y-intercept of y=-2x + 1? the slope is -2, and the y-intercept is 1
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Graphing Linear Equations
Each point on the graph of an equation is an ordered pair that makes the equation true. The graph of a linear equation is a line that indicates all the solutions of the equation. You can use the slope and y-intercept to graph a line.
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y = 2x + 1 Now look at the graph of the line.
Step 1: Look at the y-intercept and plot where the graphs cross the “y” axis. Step 2: Use the slope (rise/run) to determine the next point and plot. Remember that the slope is 2, so go up 2 and to the right 1. Step 3: Draw a line through both points. Be sure to extend pass point and put arrow at both ends.
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y = -2x + 3 Now look at the graph of the line.
Step 1: Look at the y-intercept and plot where the graphs cross the “y” axis. Step 2: Use the slope (rise/run) to determine the next point and plot. Remember that the slope is -2/1. So go down 2, and to the right 1. Step 3: Draw a line through both points. Be sure to extend pass point and put arrow at both ends.
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Find the slope of the line that passes through the points (-2, -2) and (4, 1).
When given points, it is easier to use the formula! y2 is the y coordinate of the 2nd ordered pair (y2 = 1) y1 is the y coordinate of the 1st ordered pair (y1 = -2)
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Find the slope of the line that passes through (3, 5) and (-1, 4).
-4 - ¼
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Point-Slope Form (x1 ,y1) m = rise = slope point run
y – y1 = m(x – x1) (x1 ,y1) m = rise = slope point run
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Writing in Point-Slope
Given a point and a slope, write an equation in point- slope form y – y1 = m(x – x1) Example 1: (3,8) m = 2 y – 8 = 2 (x – 3) x1, y1
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