Math Problem Statement

Jack works after school. Each day he earns a set amount, plus an hourly wage. Given the table of hours worked and corresponding pay, write a linear function f(x) that Jack can use to determine his pay.

Solution

To solve this problem, we need to determine the linear function that represents Jack's pay based on the hours he works, as shown in the table. Since it's linear, the general form of the equation should be:

f(x)=mx+bf(x) = mx + b

where:

  • mm is the hourly wage (slope),
  • bb is the set amount he earns regardless of hours (y-intercept).

Step 1: Determine the Slope (mm)

We can calculate mm by taking the difference in pay and dividing it by the difference in hours between two points. Let’s use the data points (1,18)(1, 18) and (3,38)(3, 38).

m=381831=202=10m = \frac{38 - 18}{3 - 1} = \frac{20}{2} = 10

So, Jack’s hourly wage mm is 10.

Step 2: Determine the Y-intercept (bb)

Using the slope m=10m = 10, we can substitute one of the points to solve for bb. Let’s use the point (1,18)(1, 18).

18=10(1)+b18 = 10(1) + b 18=10+b18 = 10 + b b=8b = 8

So, the y-intercept bb is 8.

Step 3: Write the Equation

The linear function for Jack’s pay is:

f(x)=10x+8f(x) = 10x + 8

Answer

The correct option is: f(x)=10x+8f(x) = 10x + 8

Would you like further details or have any questions?


Here are 5 related questions that build on this problem:

  1. How would the equation change if Jack’s hourly wage increased?
  2. What would Jack’s pay be if he worked 4 hours?
  3. How can you determine if a relationship is linear just by looking at a table of values?
  4. How would you solve if you only had one point and the slope?
  5. What does the y-intercept represent in real-life contexts?

Tip: When determining a linear relationship, calculating the slope between multiple points helps confirm consistency in rate of change.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Linear Equations
Slope-Intercept Form

Formulas

Linear equation in the form f(x) = mx + b

Theorems

Slope-Intercept Form of a Linear Equation

Suitable Grade Level

Grades 7-9