The average annual income, i, in dollars, of a lawyer with an age of x years is modeled with the following function:

i=-425x²+45,500x-650,000

according to this model, at what average age do lawyers earn their maximum average annual income?

round to the nearest year.
the average annual income, i, in dollars, of a lawyer with an age of x years is modeled with the following function:

i=-425x²+45,500x-650,000

according to this model, at what average age do lawyers earn their maximum average annual income?

round to the nearest year.