🦸 Algebra 2 Functions · Ages 14 to 17 · 0:44
Write a Linear Equation from a Point and Slope
Use slope-intercept form to write a linear equation from a point and slope. Substitute slope 2 and the point (2, 3), solve for the y-intercept, build y = 2x - 1, then check the point on the graph.
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In this video
- 0:00 Slope 2 through (2,3)
- 0:06 Start with y = mx + b
- 0:18 3 = 2(2) + b
- 0:23 So b = −1
- 0:27 The line is y = 2x − 1
Transcript
0:01 Hero Nova knows a line has slope two and passes through point two, three.
0:06 Start with slope-intercept form: y equals m x plus b.
0:13 Put in the slope two: y equals two x plus b.
0:18 Substitute the point: three equals two times two plus b.
0:23 Four plus b equals three, so b is negative one.
0:27 Build the equation: y equals two x minus one.
0:32 Check x equals two. The output is three, so the point fits.
0:38 A point and a slope are enough to write the line.
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