Let A represent Rico's age. If we write out the process of adding 24 to A, then dividing by 2, then subtracting 6, and setting that result as equal to A in algebraic notation, we get
A = (A+24)/2-6
We now wish to solve for A. First, we use the fact that
(a+b)/c = a/c+b/c
(this is effectively using the distributive property on 1/c(a+b)).
A = A/2 + 24/2 - 6
=> A = A/2 + 12 - 6
#=> A=A/2 + 6
Next, we gather all terms which include A on one side of the equation by subtracting A/2 from both sides.
A-A/2 = 6
=>A/2 = 6
Finally, we multiply by 2 to remove the coefficient of 1/2 from the A term.
A/2 * 2 = 6*2
=> A = 12
It is also good practice to check the final answer by plugging it into the original problem:
(12+24)/2-6 = 36/2-6 = 18-6 = 12
As that checks out, we now know that Rico is 12
