Line "m" has intercepts (7,0) and (0, -2)
what is the equation of line "m"?
is the point (49, -16) also on line "m"? how do you know?

The equation of a line is usually written in what's called slope-intercept form.

Slope-intercept form is written as y = mx + b where m = slope and b = the y-intercept.

The slope of a line can easily be found just by using two points on the line. The slope is equal to the rise over the run, or the difference in y over the difference in x, between the two points.



The y-intercept of the line is the point at which it intersects the y-axis. (The vertical axis.) All points on the y-axis have an x coordinate of 0, so we would then add or subtract the rise and run to a point on the line until we reached x = 0.

Fortunately, we already have this point! It's (0, -2)!



Now we just need to put our slope and y-intercept into the equation.



And to test if a point is on this line, just plug in the x and y coordinates and see if the equation is true!