If 5a = 3125, then the value of 5(a - 3) is:

First, we need to find the value of 'a'. We can do this by rearranging the equation 5a = 3125 to solve for 'a'.

Step 1: Divide both sides of the equation by 5.

5a / 5 = 3125 / 5

This simplifies to:

a = 625

Next, we substitute 'a' into the equation 5(a - 3).

Step 2: Substitute 'a' into the equation.

5(625 - 3)

Step 3: Simplify the equation inside the parentheses.

5(622)

Step 4: Multiply 5 by 622.

3110

So, the value of 5(a - 3) when 5a = 3125 is 3110.