Round to the nearest hundreth ( HELP PLEASE )

How can you tell when x and y are not directly proportional?

What is the range of the function? f(x)=-2|x+1|? a. all real numbers. b. all real numbers less than or equal to 0. c. all real numbers less than or equal to 1. d. all real numbers greater than or equal to 1

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'