linear relationships and slope form

Question

A student has a business selling snowballs during the summer. For each snowball the student sells, they makes a profit of $1.50. On the hottest day of the summer, the student sold 125 snowballs and made a profit of $187.50.

Create a model in point slope form to represent the profit the student makes, , based on the number of snowballs sold, . Use mathematics to justify your answer. 

Answer 1

slope= profit/snowball = 1.50

y = profit

x = # of snowball sold

given point(187.50, 125)- this is your x₁ and y₁

point-slope: y - y₁= m(x-x₁)

y - 125 = 1.5( x - 187.50)