# Linear Functions and Graphs

## Key Questions

• This is a linear equation. A linear equation is the representation of straight line.

This particular equation is called slope intercept form.

The $m$ in the formula is the slope.

The $b$ in the formula is where the line intersects the $y$-axis is this called the $y$-intercept.

• A linear function models a straight line that has a constant slope or rate of change.

There are various forms of linear equations.

Standard Form

$A x + B y = C$

where $A , B \mathmr{and} C$ are real numbers.

Slope Intercept Form

$y = m x + b$

where $m$ is the slope and $b$ is the $y$-intercept

Point Slope Form

$\left(y - {y}_{1}\right) = m \left(x - {x}_{1}\right)$

where $\left({x}_{1} , {y}_{1}\right)$ is any point on the line and $m$ is the slope.