Need help i don't get it

The total cost of 4 persons is 12
From the graph, we have the following points:
(1, 3), (2, 6) and (3, 9)
This means that the total cost of x person is 3 multiplied by the number of person (x)
i.e.
Total cost = 3 * Total person
When the number of people is 4
This gives
Total cost = 3 * 4
Evaluate
Total cost = 12
Hence, the total cost of 4 persons is 12
Read more about linear equations at:
https://brainly.com/question/14323743
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