Which relation is a function?

{ (1,2), (2, 1), (1, 3), (3,1) }

{ (1,2), (3, 4), (5, 6), (1,8) }

{ (0,2), (0, 4), (0, 6), (0,8) }

{ (1,2), (2, 3), (3, 4), (4,5) }

Ezra is participating in a marathon walk for charity. He knows he can walk 3 miles in 45 minutes. At the rate, how long will it take Ezra to walk 26 miles

A train travels at a constant rate of 45 miles per hour.

What is 950,000,000 in scientific notation?

The table below shows the number of years after the year 2000 and the percentage of people of a country owning homes: Number of years after 2000 (x) 2 4 5 1 3 7 6 Percentage of people owning homes (y) 24% 32% 36% 20% 28% 44% 40% What is the

An amusement park has two types of season passes. Plan 1 costs a one-time fee of $129.00 for admission plus $7.00 every trip for parking. Plan 2 costs a one-time fee of $50.00 for parking plus $22.00 every trip for admission.

F (x) = 2/x at x = - 2

Write each number in expanded form 670,200,640

A box is tossed upward from a cliff that is 15 meters high, at a speed of 4 meters per second. The height of the box is given in meters by h (t) = -4.9t^2+4t+15 where t is seconds. What is the height of the box at 1 second?

Paulo's father bought 8 pizzas and 12 bottles of juice for the class party. Each pizza coast $9 and each bottle of juice cost$2 Paulo's father paid $100-bill. How much change did he get back

Two numbers are in the ratio 7:8. Find the numbers if their sum is 45.