Example

Graphing y=0.2x+45y = 0.2x + 45 Using its Slope and y-Intercept

To graph y=0.2x+45y = 0.2x + 45, use a coordinate grid with axes extended from about 80-80 to 8080, since the y-intercept at 4545 does not fit on a standard 10-10 to 1010 grid.

Step 1 — Find the slope-intercept form. The equation y=0.2x+45y = 0.2x + 45 is already in the form y=mx+by = mx + b.

Step 2 — Identify the slope and y-intercept. The slope is m=0.2m = 0.2 and the y-intercept is (0,45)(0, 45).

Step 3 — Plot the y-intercept. Mark the point (0,45)(0, 45) on the coordinate plane.

Step 4 — Count out the rise and run. The slope m=0.2m = 0.2 can be written as the fraction 210\frac{2}{10}. However, given the large scale of the graph, using the equivalent fraction 1050\frac{10}{50} produces step sizes that are easier to work with on the extended grid. The rise is 1010 and the run is 5050.

Step 5 — Mark the second point. Starting at (0,45)(0, 45), move up 1010 units and right 5050 units to reach (50,55)(50, 55).

Step 6 — Connect the points with a line. Draw a straight line through (0,45)(0, 45) and (50,55)(50, 55).

This example demonstrates two practical techniques: converting a decimal slope to a fraction (0.2=2100.2 = \frac{2}{10}), and then replacing that fraction with an equivalent one (1050\frac{10}{50}) whose rise and run better fit the graph's extended scale.

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Updated 2026-04-21

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