1. ## graphing

how do i find the equation of a line, that is on a grid?

2. Originally Posted by angiek723
how do i find the equation of a line, that is on a grid?
recall, a line is of the form $y = mx + b$ where $m$ is the slope and $b$ is the y-intercept.

identify two points the line passes through, this is usually easy on a grid.

call one point $(x_1,y_1)$ and the other $(x_2,y_2)$

find the slope:

$m = \frac {y_2 - y_1}{x_2 - x_1}$

then plug that value for m into the point slope form:

$y - y_1 = m(x - x_1)$

solve for $y$ and you're done