n + n + 3 + 2n = (sum of age)
First change the problem and add 1 in front of the variables (n)
1n + 1n + 3 + 2n = (sum of age)
Next add the like terms which are 1n, 1n, and 2n
1n + 1n = 2n
2n + 2n = 4n
Now 3 is left by itself add it to the problem
4n + 3
SIMPLIFIED EXPRESSION IS 4n + 3