I think it’s 9+2 because it say sum
If m =2 insert m so 4+4-3+5
answer is 5
<span>We know that the runner completed her first race in 17.8 seconds and that she completed her second race in 16.9 seconds. Then the difference between the first race and the second race is .9 seconds. Now we divide .9 by 17.8 and multiply by 100 to get the percent decrease. We get 5.06%. The percent decrease in her time is 5%.</span>