Acompany uses the function c(x)=20.50+2000, where c is the cost and x is the number of units it produces, to determine its daily costs. find the inverse of the function and determine how many units are produced when the cost is $625,000.

You left it out, but I'm thinking that there must be an 'x' next to the '20.50' in the function.  I'm so sure of it that I'll assume it, as I proceed to answer the question:

C(x) = 20.50x + 2,000

Subtract  2,000 from each side:      C - 2,000  =  20.50 x

Divide each side by  20.50 :        x  =  (C - 2,000) / 20.50

When C = $625,000 . . .

x = (625,000 - 2,000) / 20.50  =  623,000 / 20.50  =  30,390.2439

30,390 complete units are produced, and there are  5  bucks left over,
to split up among all the loyal employees who worked with such diligence and dedication to make it happen.  The company's senior management will graciously add each worker's share to his gross pay before taxes for the second month following the close of the current quarter, with a photocopied note inserted in the pay envelope, expressing management's sincere thanks to everyone, an admonition not to spend it all in one place, and a reminder that no matter how many festivals to their god they need to go out to the desert to celebrate, their tally of bricks for the next quarter shall not be diminished.