Algebra 1 / Unit 5: Linear Functions
5.2 Slope-Intercept Form
Notes
Slope-intercept form is $y = mx + b$, where $m$ is the slope and $b$ is the $y$-intercept.
- To graph: plot $(0, b)$, then use rise over run to find more points.
- To write an equation from the slope and a point, substitute to find $b$.
- In context, $b$ is often the starting amount and $m$ the rate.
Practice
What are the slope and $y$-intercept of $y = -3x + 7$?
Match it to $y = mx + b$.
Write the equation of the line with slope 4 through $(2, 3)$.
$3 = 4(2) + b$, so $b = -5$.
Rewrite $2x + y = 6$ in slope-intercept form.
Subtract $2x$ from both sides.
Ready for more? Take the Unit 5 test.