Which of the following relations is a function?
A. (0,4), (-1, 6), (0, 3), (-7, 2)
B. (6,1), (-1, 4), (0, 1), (6, 2)
C. (0,4), (-1, 2), (6, 1), (-7, 2)
D. (0,0), (-1, 3), (6, 1), (-1,5)

Can some one me with these questions

Acompany charges $0.10 for each letter engraved. bobby plans to spend no more than $5.00 on the engraving on a jewelry box. write and solve an inequality to find the maximum number of letters he can have engraved.

Use a calculator to verify that σ(x) = 62, σ(x2) = 1034, σ(y) = 644, σ(y2) = 93,438, and σ(x y) = 9,622. compute r. (enter a number. round your answer to three decimal places.) as x increases from 3 to 22 months, does the value of r imply that y should tend to increase or decrease? explain your answer. given our value of r, y should tend to increase as x increases. given our value of r, we can not draw any conclusions for the behavior of y as x increases. given our value of r, y should tend to remain constant as x increases. given our value of r, y should tend to decrease as x increases.