Question

A company has found that its rate of expenditure in hundreds of dollars on a certain type of job is given by e’(x)=2x+7, where x is the number of days since it start of the job. Find the total expenditure if the job takes three days

Answer 1

The given equation represents the rate of expenditure in hundreds of dollars for a certain type of job:

$E^{\prime}(x)=2x+7$

→ x represents the number of days since the start of the job

You have to determine the expenditure, E'(X), when the job takes three days (x=3), to do so replace the number of days into the equation and solve for E'(x)

$\begin{gathered} E^{\prime}(x)=2x+7 \\ E^{\prime}(3)=2*3+7 \\ E^{\prime}(3)=6+7 \\ E^{\prime}(3)=13 \end{gathered}$

The total expenditure for a job that takes 3 days will be 13 hundred dollars.