For problems involving algebra, you have to formulate algebraic equations to be able to solve the problem. Algebraic equations are mathematical terms which include variables to denote the unknown numbers.
For this problem, you are to find the total cost which consists of cost for the gun rent and cost for the paintballs. Hence, your equationmust consist of two terms. The equation must be:
Total cost = 100x + 1000
The term x denotes the number of guns. Hence, it must be multiplied with 100 to determine the cost. On the otherhand, the constant 1000 is for the paintballs. Since it was given that each team must have 2000 paintballs, then it follows that they must pay 1000 Php.
