Which relation is a function?

a.
{(1, 2); (2, 3); (3, 4); (2, 5)}

b.
{(1, 2); (2, 3); (3, 4); (4, 5)}

c.
{(1, 2); (1, 3); (1, 4); (1, 5)}

d.
{(1, 2); (3, 2); (3, 3); (4, 2)}

Let the mean of the population be 38 instances of from 6" - 9" hatchings per nest, and let the standard deviation of the mean be 3. what sample mean would have a confidence level of 95% or a 2.5% margin of error?

Desmond wants to sell his car that he paid $8,000 for 2 years ago. the car depreciated, or decreased in value, at a constant rate each month over a 2-year period. if x represents the monthly depreciation amount, which expression shows how much desmond can sell his car for today? 8,000 + 24x 8,000 - 24x 8,000 + 2x 8,000 - 2xdesmond wants to sell his car that he paid $8,000 for 2 years ago. the car depreciated, or decreased in value, at a constant rate each month over a 2-year period. if x represents the monthly depreciation amount, which expression shows how much desmond can sell his car for today? 8,000 + 24x 8,000 - 24x 8,000 + 2x 8,000 - 2x

Simplify this expression. 8x 16(x + y)