Amos scored 100 points while playing 3 rounds of a game. Points
Round 1 - 30
Round 2 - 25
Round 3 - ?
Total - 100

How many points did he score in round 3?

Complete the steps to solve the problem.

1. What do you need to solve for this problem? Choose a variable to represent this unknown value.

2. Using the variable you chose, write an equation to represent this situation. (Hint: You may want to put the number of points in each round on one side and the total number of points on the other.)

3. Solve this equation to find how many points Amos scored in round 3. Show your work.