(1 point) A function is said to have a horizontal asymptote if either the limit at infinity exists or the limit at negative infinity exists. Show that each of the following functions has a horizontal asymptote by calculating the given limit. -4x lim r-+0 2 + 2x 5x - 3 lim r+ 0or3 + 9x- 7 2 - 4x - 9 lim I +0O 5 - 972 2 + 5x lim I-+0O 4- 15x lim Vaz+ 5x 1 4 00 4 - 15x