# Representation of phenomena - Examples, Exercises and Solutions

A linear function describes the relationship between $X$ and $Y$.
Therefore, we can represent all sorts of different phenomena in life with the help of the linear function.
The representation of phenomena with the help of linear functions is expressed in mathematics in word problems, using graphs of the functions.
Thus, we can find the various relationships between the functions.

Representing phenomena using linear functions actually allows us to simplify many word questions using a simple linear graph. From the graph, we can very easily calculate the slope, which is actually the rate of change and even many other parameters.

## Practice Representation of phenomena

### Exercise #1

The graph below represents the price of apples depending on the quantity.

What is the price of 7 kg of apples?

8

### Exercise #2

The graph below depicts the price of apples depending on the quantity.

How many kg of apples can you buy for \$9?

8

### Exercise #3

The graph below depicts the price of tomatoes as a function of quantity, with each line representing the prices at different shops.

Where is it cheaper to buy 7 kg of tomatoes?

In the red shop

### Exercise #4

A car leaves Madrid for Barcelona. During the journey, the driver has a break.

For how many hours did the driver rest?