A window cleaner has enough supplies to clean 21 windows per office building on a certain number of buildings. They can also clean the windows of a school with 42 windows. Altogether, there are enough supplies to clean 126 windows. How many office buildings can be washed? Identify the equation that would be used to solve this problem algebraically.

Answer 1

Let the number of office buildings be x.
Since each office building has 21 windows, the total number of windows in the office buildings is 21x.
The number of windows in the school is 42.
Therefore, the total number of windows cleaned is 21x + 42 = 126.
Subtracting 42 from both sides of the equation, we get 21x = 84.
Dividing both sides of the equation by 21, we get x = 4.
Therefore, there are 4 office buildings that can be washed.
The equation that would be used to solve this problem algebraically is 21x + 42 = 126.