Moving Straight Ahead Notes

Equations – Day 5 Name ______Assignment Date ______Period ______

The number of times a cricket chirps in a minute is a function of the temperature. You can use the formula

n = 4t – 160

To determine the number of chirps, n, a cricket makes in a minute when the temperature is t degrees Fahrenheit. If you want to estimate the temperature by counting cricket chirps, it is easier to use the following form of the equation:

1 t = n + 40 4

1. At 60F, how many times does a cricket chirp in a minute?

2. What is the temperature if a cricket chirps 150 times in a minute?

3. A what temperature does a cricket stop chirping?

4. Sketch a graph of the equation with number of chirps on the x-axis and temperature on the y-axis. What information does the y-intercept give you? Equations – Day 5 Name ______Assignment Date ______Period ______

At Fabulous Fabian’s Bakery, the cost, C, and revenue, R, to make and sell N cakes per month are given by the equations below.

C = 800 + 3.20N and R = 8.50N

5. Fabian sold 100 cakes in January. What were his cost and revenue? Did he make a profit?

6. In April, Fabian’s revenue was $1105. How many cakes did he sell?

7. What was the cost of producing the number of cakes in April?

8. What is the break-even point between cost and revenue?

9. In each equation, what information do the y-intercept and the coefficient of N give you?

The maximum weight allowed in an elevator is 1500 pounds.

10. If ten children are in the elevator, how many adults can get in? Assume the average weight per adult is 150 pounds and the average weight per child is 40 pounds.

11. If six adults are in the elevator, how many children can get in?

12. Write an equation for the number of adults, A, and the number of children, C, the elevator can hold.