Answer:
M(x) = 29480 units
Step-by-step explanation:INCOMPLETE QUESTION.
Information describing the equation of maintenance costs for the type of building is needed, we can either work with a maintenance costs equation
or with any other equation from which to get the maintenance costs equation.
Particularly similar statement problem give M´(x) = 90*x² + 5000, therefore if we integrate such equation we get M(x) as maintenance cost equation. We will do that then
M´(x) = 90*x² + 5000
∫M´(x) = M(x) = ∫(90*x² + 5000 ) dx
but we require costs from the end of second year up to the end of the 7 th year then
M(x) = ∫₃⁷ (90*x² + 5000) dx
M(x) = (90/3 )*x³ + 5000*x) |₃⁷
M(x) = 30*(7)³ + 5000* (7) - 30*(3)³ - 5000*3
M(x) = 10290 + 35000 - 810 - 15000
M(x) = 29480 $