Question

In a certain urban are, the relationship between , number of students ,x, in thousands, and the number schools, y, has an x-intercept of -4 and a y-intercept of 3. Write an equation for this relationship in standard form.

Answer 1

-12 = 3x - 4y

Explanation:

Two points on the graph are (-4, 0) and (0, 3). Moving from the first point to the second, we see x (the 'run') increase by 4 and y (the 'rise') increase by 3. Thus, the slope of this line is m = rise / run = 3/4.

Using the point slope form, we get:

y - 3 = (3/4)(x - 0), or

4y - 12 = 3x, or

-12 = 3x - 4y (which is in Standard Form).