Liam cleaned 21 windows per office building for a certain number of buildings he also cleaned 42 windows of a school altogether he cleaned 126 windows how many office buildings did he clean identify the equation that could be used to solve this problem algebraically

To find out how many office buildings Liam cleaned, we need to set up an equation based on the information provided.

Let \( x \) be the number of office buildings Liam cleaned. Since he cleaned 21 windows per office building, the total number of windows cleaned from the office buildings would be \( 21x \).

In addition, Liam also cleaned 42 windows from a school. The total number of windows cleaned was 126.

We can write the equation based on this information:

\[
21x + 42 = 126
\]

Now, to solve for \( x \), we can rearrange the equation:

1. Subtract 42 from both sides:

\[
21x = 126 - 42
\]
\[
21x = 84
\]

2. Divide both sides by 21:

\[
x = \frac{84}{21}
\]
\[
x = 4
\]

Therefore, Liam cleaned **4 office buildings**.

The equation \( 21x + 42 = 126 \) can be used to solve the problem algebraically.