Question

Shelly sells ice cream bars at the beach. In addition to a fixed salary, she earns a commission for each ice cream bar she sells. The table shows Shelly's total earnings, y, from selling x bars of ice cream:

Which equation best shows the relationship between x and y?



Ice Cream Sales and Earnings
Number of Bars Sold(x) Total Earnings(dollars) (y)




0 60


1 65

2 70

3 75



y=x+70
y=5x+60
y+5x+70
y+x+60

Answer 1

Simply, the question wants you to write an equation for the points they gave you.

The points are:
(0,60)
(1,65)
(2,70)
(3,75)

The first thing we need to do is to find the slope.


`\sf{Slope =(y_2-y_1)/(x_2-x_1) =(65-60)/(1-0) =(5)/(1) =\boxed{\bf{5}}`

The slope is 5.

If we write an equation in the form of y = mx + b, where m is the slope, and b is the y-intercept, we would have so far:

y = 5x + b

Now, we need to find the y-intercept.
We are given the point (0,60)
That point lies on the y-axis, and therefore, 60 is the y-intercept.

Our final equation is y = 5x + 60.