Any help is appreciated.

. A medical contractor is starting production on a portable type of MRI device. Using information gathered during the assembly of the first 16 units, the production engineer obtained the following function describing the rate of labor use: L'(x) = 20002-1/2 For example, after assembly of 16 units, the rate of assembly is 500 labor-hours per MRI device, and after 25 units, the rate of assembly should be 400 labor-hours per MRI device. If 20,000 hours were required to assemble the first 16 units, how many labor-hours L(x) will be required to assemble a units? The first 25 units