5a-a-2a=18

5a - 3a = 18

2a = 18

a = 18/2

a = 9

873 divided by 24

that's 36.375

To solve the equation 5a - a - 2a = 18, we need to simplify the expression on the left side and then isolate the variable "a".

Step 1: Combine like terms on the left side.
5a - a - 2a simplifies to 2a.

Now our equation becomes:
2a = 18

Step 2: Solve for "a" by isolating it.
To isolate "a", divide both sides of the equation by 2:
2a/2 = 18/2

This simplifies to:
a = 9

Therefore, the solution to the equation 5a - a - 2a = 18 is a = 9.