Tim's phone service charges $23.86 plus an additional $0.17 for each text message sent per month. If Tim's phone bill was $28.11, which equation could be used to find how many text messages, x, Tim sent last month? A.
$23.86x + $0.17 = $28.11

B.
$0.17x - $23.86 = $28.11

C.
$0.17x + $23.86 = $28.11

D.
$23.86x - $0.17 = $28.11

GIVING BRAIN PLZ ASAP

The polynomial function of least degree with a leading coefficient of 1 is: f(x) = x3 + ax2 + bx + c

At the olympic games, many events have several rounds of competition. one of these events is the men's 100-meter backstroke. the upper dot plot shows the times (in seconds) of the top 8 finishers in the final round of the 2012 olympics. the lower dot plot shows the times of the same 8 swimmers, but in the semifinal round. which pieces of information can be gathered from these dot plots? (remember that lower swim times are faster.) choose all answers that apply: a: the swimmers had faster times on average in the final round. b: the times in the final round vary noticeably more than the times in the semifinal round. c: none of the above.

Does the point (1, sqrt 7) lie on circle shown.