A business analyst makes \[tex]$20 an hour for the first 42 hours he works during a week and \$[/tex]28 an hour for each hour worked over 42 hours. Which piecewise equation models his total weekly pay [tex]\( y \)[/tex] in dollars as it relates to the number of hours [tex]\( x \)[/tex] that he has worked during the week?

A. [tex]\[ y=\left\{\begin{array}{ll}
20x & 0 \leq x \leq 42 \\
28(x-42) + 840 & x \ \textgreater \ 42
\end{array}\right. \][/tex]

B. [tex]\[ y=\left\{\begin{array}{ll}
20x & 0 \leq x \leq 42 \\
28x & x \ \textgreater \ 42
\end{array}\right. \][/tex]

C. [tex]\[ y=\left\{\begin{array}{ll}
20x & 0 \leq x \leq 42 \\
28(x-42) & x \ \textgreater \ 42
\end{array}\right. \][/tex]

D. [tex]\[ y=\left\{\begin{array}{ll}
20x & 0 \leq x \leq 42 \\
28x + 840 & x \ \textgreater \ 42
\end{array}\right. \][/tex]



Answer :

To find the correct piecewise equation that models the business analyst's total weekly pay [tex]\( y \)[/tex] as it relates to the number of hours [tex]\( x \)[/tex] worked, we will break down the problem step by step:

1. Determine the pay rate for the first 42 hours:
- The analyst earns [tex]$20 per hour for the first 42 hours. - So, if \( 0 \leq x \leq 42 \), the total pay \( y \) is given by: \[ y = 20x \] 2. Determine the pay rate for hours worked beyond 42 hours: - For hours worked beyond 42, the analyst earns $[/tex]28 per hour.
- This rate applies only to the hours exceeding 42.
- Therefore, if [tex]\( x \)[/tex] hours are worked where [tex]\( x > 42 \)[/tex]:
- The analyst earns $20 per hour for the first 42 hours, so the pay for these hours is [tex]\( 20 \times 42 \)[/tex].
- The total pay for the first 42 hours is:

[tex]\[ 20 \times 42 = 840 \text{ dollars} \][/tex]

- For the hours exceeding 42, let [tex]\( x - 42 \)[/tex] be the number of overtime hours.
- The pay for the overtime hours is [tex]\( 28 \times (x - 42) \)[/tex].
- Hence, the total pay [tex]\( y \)[/tex] for [tex]\( x > 42 \)[/tex] is:

[tex]\[ y = 28(x - 42) + 840 \][/tex]

3. Formulate the piecewise function:
- Combining the above pay calculations into the piecewise function, we get:

[tex]\[ y = \left\{\begin{array}{ll} 20x & \text{if } 0 \leq x \leq 42 \\ 28(x-42) + 840 & \text{if } x > 42 \end{array}\right. \][/tex]

The correct piecewise equation that models the analyst's total weekly pay is then:

[tex]\[ A. \quad y = \left\{\begin{array}{ll} 20x & 0 \leq x \leq 42 \\ 28(x-42) + 840 & x > 42 \end{array}\right. \][/tex]