Question

David had a coupon for the grocery store. He graphed on the x-axis what his total bill would be if he didn’t use the coupon and graphed on the y-axis what his total bill would be if he used the coupon.

Based on the information in the graph, if David’s bill came to $66 after the coupon was applied, how much would his bill have been if he hadn’t used the coupon?

a. $64
b. $65
c. $67
d. $68

Answer 1

Option d. $68

Explanation:

Answer 2

Option d. $68

Explanation:

From the graph attached we will define the relation between Bill without the coupon and Bill with coupon.

Since graph is a linear function showing a straight line will be in the form of a straight line in the form of y = mx + c

where m = slope

c = y- intercept

Given line in the graph is passing through two points (2, 0) and (4, 2).

therefore m = (2-0)/(4-2) = 2/2 = 1

Now the line passing through (2, 0) and with slope 1 equation will be

0 = 1×2 + c ⇒ c = -2

Now the relation between bills with and without coupon can be represented by y = x - 2

Now we have to find the amount of bill without coupon if the bill with coupon was $66

Now with the help of the equation 66 = x - 2

x = 66 + 2 = $68