The function below shows the cost of a hamburger with different numbers of toppings (t).

f(t) = 1.90 + 1.40t

a. What is the y-intercept, and what does it mean?

b. What is the slope, and what does it mean?

c. If Jodi paid $3.30 for a hamburger, how many toppings were on Jodi’s hamburger?

1 answer

Let's analyze the function \( f(t) = 1.90 + 1.40t \) step by step.

a. Y-Intercept

The y-intercept occurs when \( t = 0 \). By substituting \( t = 0 \) into the function:

\[ f(0) = 1.90 + 1.40(0) = 1.90 \]

Interpretation: The y-intercept of 1.90 means that the cost of a hamburger with no toppings (t = 0) is $1.90.

b. Slope

The slope of the function is the coefficient of \( t \), which is 1.40.

Interpretation: The slope of 1.40 indicates that for each topping added to the hamburger, the cost increases by $1.40.

c. Determine the number of toppings for Jodi's hamburger

We know that Jodi paid $3.30 for her hamburger. We can set up the equation using the function:

\[ f(t) = 3.30 \] \[ 1.90 + 1.40t = 3.30 \]

Now, we solve for \( t \):

  1. Subtract 1.90 from both sides: \[ 1.40t = 3.30 - 1.90 \] \[ 1.40t = 1.40 \]

  2. Divide both sides by 1.40: \[ t = \frac{1.40}{1.40} = 1 \]

Conclusion: Jodi's hamburger had 1 topping.