Select the correct answer.

A company manufactures computers. Function [tex]$N$[/tex] represents the number of components that a new employee can assemble per day. Function [tex]$E$[/tex] represents the number of components that an experienced employee can assemble per day. In both functions, [tex]$t$[/tex] represents the number of hours worked in one day.

[tex]\[
\begin{array}{l}
N(t) = \frac{10t}{t+4} \\
E(t) = \frac{10t}{t+3}
\end{array}
\][/tex]

Which function describes the difference in the number of components assembled per day by the experienced and new employees?

A. [tex]$D(t) = \frac{10(2t+13)}{(t+3)(t+4)}$[/tex]

B. [tex]$D(t) = \frac{10t(2t-13)}{t+t}$[/tex]

C. [tex]$D(t) = \frac{10t(2t+13)}{t+3}$[/tex]

D. [tex]$D(t) = \frac{10t(2t-13)}{(t+3)(t+4)}$[/tex]



Answer :

To determine the function that describes the difference in the number of components assembled per day by an experienced employee and a new employee, follow these steps:

1. Write down the given functions:
- [tex]\( N(t) = \frac{10t}{t + 4} \)[/tex]
- [tex]\( E(t) = \frac{20t}{t + 3} \)[/tex]

2. Set up the difference function [tex]\( D(t) \)[/tex]:
[tex]\[ D(t) = E(t) - N(t) \][/tex]

3. Substitute the given functions into the difference function:
[tex]\[ D(t) = \frac{20t}{t + 3} - \frac{10t}{t + 4} \][/tex]

4. Find a common denominator to combine the fractions:
The common denominator for [tex]\((t + 3)\)[/tex] and [tex]\((t + 4)\)[/tex] is [tex]\((t + 3)(t + 4)\)[/tex].

5. Rewrite each fraction with the common denominator:
[tex]\[ D(t) = \frac{20t(t + 4)}{(t + 3)(t + 4)} - \frac{10t(t + 3)}{(t + 3)(t + 4)} \][/tex]

6. Combine the fractions:
[tex]\[ D(t) = \frac{20t(t + 4) - 10t(t + 3)}{(t + 3)(t + 4)} \][/tex]

7. Expand the numerators:
[tex]\[ 20t(t + 4) = 20t^2 + 80t \][/tex]
[tex]\[ 10t(t + 3) = 10t^2 + 30t \][/tex]

8. Subtract the numerators:
[tex]\[ (20t^2 + 80t) - (10t^2 + 30t) = 20t^2 + 80t - 10t^2 - 30t = 10t^2 + 50t \][/tex]

9. Write the final expression for [tex]\( D(t) \)[/tex]:
[tex]\[ D(t) = \frac{10t^2 + 50t}{(t + 3)(t + 4)} \][/tex]

Next, simplify the numerator [tex]\( 10t^2 + 50t \)[/tex]:

[tex]\[ D(t) = \frac{10t(t + 5)}{(t + 3)(t + 4)} \][/tex]

After simplifying, we test it against the given options:

A. [tex]\( D(t) = \frac{10(2t + 13)}{(t + 3)(t + 4)} \)[/tex]
B. [tex]\( D(t) = \frac{10t(2t - 13)}{t + t} \)[/tex]
C. [tex]\( D(t) = \frac{10t(2t + 13)}{t + 3} \)[/tex]
D. [tex]\( D(t) = \frac{10t(2t - 13)}{(t + 3)(t + 4)} \)[/tex]

By examining the given differential equations, we can confirm that none of these equations match the simplified expression.

Thus, the answer is:
```
None of the given options match.
```