Question

Pizza General charges 10 dollars per medium pizza.
Find the slope, or the change in vertical distance for a given change in horizontal distance. In other words, by how much does the total cost increase every time you buy 1 more pizza?
1
10
x
y
m
(1, 10)(2, 20)
0
1
2
3
4
5
6
7
8
9
10
11
0
5
10
15
20
25
30
35
40
45
50
55
60
Number of pizzas
Total cost in dollars
Slope =
vertical distance
horizontal distance
=

Answer 1

To find the slope of the total cost as you buy additional medium pizzas from Pizza General, we need to analyze the relationship between the number of pizzas purchased and the total cost.

### Given:
- **Cost per medium pizza**: $10

### Points:
- When you buy **1 pizza**, the total cost is **$10**. This can be represented as the point \((1, 10)\).
- When you buy **2 pizzas**, the total cost is **$20**. This can be represented as the point \((2, 20)\).

### Slope Calculation:
The slope \( m \) is calculated by the formula:

\[
m = \frac{\text{Change in total cost}}{\text{Change in number of pizzas}}
\]

Using the points \((1, 10)\) and \((2, 20)\):
- Change in total cost = \(20 - 10 = 10\)
- Change in number of pizzas = \(2 - 1 = 1\)

Substituting these values into the slope formula:

\[
m = \frac{10}{1} = 10
\]

### Conclusion:
The slope \(m\) is **10**. This means that for every additional pizza you buy, the total cost increases by **10 dollars**.