We will say that x is the salary before the raise, to calculate how much the salary grows, we just have to take the given percent from x, in this case, the payment increased by 4% (0.04 expressed in decimal form) then the increased amount would be x times 0.04.
Salary increase = x*0.04 = 0.04x
Adding 0.04 x to the original salary x (before applying the increase) we get the actual monthly salary, $2,496, then we can formulate the following expression:
Current salary = original salary + salary increase
2,496 = x + 0.04x
From this equation, we can solve for x like this:
1. Factoring x on the right side of the equation:
2,496 = x(1+0.04)
2. making the sum inside the parentheses:
2,496 = x*1.04
3. Dividing both sides by 1.04:
2,496 / 1.04 = x * 1.04 / 1.04
2400 = x
x = 2400
Then, Linda was making $2400 before the pay increase