Question

The function f(x) is shown in the graph.
What is the equation for f(x)?

Answer 1

It's a linear graph, so we can use the slope-intercept form. Let's find the y-intercept first, which happens ar y = -3. Now let's find the slope. To do so, let's pick two points on the graph (relatively easy ones): (0, -3) and (5, -7).

Let's find the slope:

`m = (y_2-y_1)/(x_2-x_1) = (-7-(-3))/(5-0) = -(4)/(5)`

Let's write it in slope-intercept form. Recall that slope-intercept form is:

`y = mx+b`

Where m = slope and b = y-intercept. We have all the parts, so let's write it:

`y = -(4)/(5)x - 3`