A successful author invests some of his earnings in two accounts for 1 year. the function f(x)=.05 models the interest he earns on x dollars invested in the first account. the function g(x)=.075(x+2500) models the interest he earns from the second account, in which he invests $2500 more than in the first account.
Evaluate (f+g)(18,500) and interpret what it means in this situation