The slope-intercept form is a specific way to express a linear equation. It is written as \( y = mx + b \). In this form:
- \( m \) represents the slope of the line. This tells us how steep the line is. A positive \( m \) means the line goes upwards as you move to the right. A negative \( m \) means the line goes downwards.
- \( b \) is the y-intercept. This is the point where the line crosses the y-axis. It shows us what the value of \( y \) is when \( x \) is zero.
To convert a standard linear equation \( Ax + By = C \) into the slope-intercept form, we rearrange the equation to isolate \( y \) on one side. For example, with the equation \(-x + 3y = -40\), by solving for \( y \), we find that \( y = \frac{1}{3}x - \frac{40}{3} \). This clearly shows the slope \( \frac{1}{3} \) and the y-intercept \( -\frac{40}{3} \). Being aware of these components helps in graphing lines quickly and understanding their behavior.