Linear functions are equations whose graph is a straight line. Each x-value has an assigned y-value.
General function equation
Every linear function has the general function equation:
$m ...$ slope of the straight line
$n ...$ the y-intercept (ordinate intercept)
With this equation, the $y$-value of a linear function can be determined using the $x$-value, $m$ and $n$. The line intersects the y-axis at point $P(0|n)$.