Practice Quiz 3 of 4

Look at the table for y = x2:
x: 1, 2, 3, 4, 5
y: 1, 4, 9, 16, 25
Is this a linear function?

A hot air balloon travels y = 85x miles in x hours. How far does it go in 7 hours?

Which equation is linear?

Solve −4x + y = 11 for y. What is y when x = 2?

y = 4x, where x is time and y is gallons of water in a tank. Discrete or continuous?

A tree frog’s migration is shown. What constant change in distance (km) goes with each 1-day change in time?

Find the x-intercept of −5x + 6y = 60.

Find the x-intercept of 8x + 4y = −56.

Arlo found the x-intercept of 9x + 12y = 144 like this: 9(0) + 12y = 144 → y = 12, “x-intercept is 12.” What is the correct x-intercept?

Temperature in an experiment: y = 5⁄2x − 70 (°C after x hours). After how many hours does it reach 0 °C?

Which equation matches this graph?

A sail’s slanted edge follows 10x + 4y = 240 (feet). The sail is the triangle formed by this line and the two axes. What is its area?

Postage table — Years after 2000 (x): 3, 4, 6, 8, 13  |  Cost in cents (y): 37, 37, 39, 42, 46.
What is the rate of change from 2006 to 2008?

Find the slope of the line. (Decimal or fraction is fine.)

Use the slope formula to find the slope through (−4, 7) and (2, −8).

Describe the slope of the line through (5, 9) and (5, −2).

A graph of money earned shows (4, 110) and (8, 170) (hours worked, dollars). What is the slope?

Crickets chirp more when it’s warmer: 40 °F → 0 chirps/min, 50 °F → 40, 60 °F → 80, 70 °F → 120. What is the slope?

Hikers: 0.5 hr → 3 km, 1 hr → 5 km, 2 hr → 7 km, 3 hr → 13 km. Which segment has the greatest slope?

A student found the slope through (4, 3) and (−2, 15) as (4 − (−2)) / (3 − 15) = −½. What is the correct slope?