Answer:
Step-by-step explanation:
The first group consists of Petra and 4 friends, so the total number of members is 5, therefore the left side of equation should be:
The second group consists of 4 people, Valentina and 3 friends, therefore the right side of the equation should be:
Solving the equation to find the cost of a ticket for Petra's group:
Cost of a ticket is $8.5