Apoor family with an income of 15,500 per year who purchase the average amount of lottery tickets for their income bracket

y = - 2x + 13

Step-by-step explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Here m = - 2, thus

y = - 2x + c ← is the partial equation of the line

To find c substitute (9, - 5) into the partial equation

- 5 = - 18 + c ⇒ c = - 5 + 18 = 13

y = - 2x + 13 ← equation in slope- intercept form