Let x be the number of office buildings.
The total number of windows in the office buildings is 21x.
The equation to solve this problem algebraically is 21x + 42 = 126.
The total number of windows in the office buildings is 21x.
The equation to solve this problem algebraically is 21x + 42 = 126.
Since each office building has 21 windows, the number of windows in the office buildings can be calculated as 21x.
Since there is also a school with 42 windows, the total number of windows to be cleaned is 21x + 42.
The problem states that there are enough supplies to clean 126 windows, so we can set up the equation:
21x + 42 = 126
This is the equation that can be used to solve the problem algebraically.
The school has 42 windows, so the total number of windows in the office buildings and the school would be 21x + 42.
We also know that there are enough supplies to clean 126 windows in total. Since the supplies are sufficient for cleaning all the windows, we can set up the equation:
21x + 42 = 126
To solve for x, we can first subtract 42 from both sides of the equation:
21x = 126 - 42
Simplifying further:
21x = 84
Finally, to solve for x, we divide both sides of the equation by 21:
x = 4
So, there are 4 office buildings that can be washed.