What is a linear equation?
A linear equation graphs as a straight line.
Common form:
y = mx + b
m = slope
b = y-intercept
Slope
The slope tells how steep the line is.
Slope = change in y divided by change in x
Positive slope: line goes up left to right
Negative slope: line goes down left to right
Y-intercept
The y-intercept is where the line crosses the y-axis.
It occurs when x = 0.
How to graph a linear equation
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Find the y-intercept and plot it
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Use the slope to find another point
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Draw a straight line through the points
Example
y = 2x + 1
y-intercept = 1 → point (0,1)
Slope = 2 → rise 2, run 1
Next point = (1,3)