What is 21 1/2 -15 7/10?

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.

X= 3y - 6 2x - 4y = 8 solve the system of equations using substitution. a) (-12,-2) b) (15,7) c) (21,9) d) (24,10)

Lines a and b are perpendicular. if the slope of line a is 3, what is the slope of line b?