Iam stuck on this question. i don't understand how to do it 10m/s to ft/s

3× __ -2=15 7 2× __+1=7 5 7× =22 15 5× __+10=2 8 × __+4=20 6 × =10 3 × __+2=8 6 × __+8=8 9 × __+7=20 6

Ricardo ran the 400 meter race 3 times his fastest time was 54.3 seconds his slowest time was 56.1 seconds if his average time was 55.0 seconds what was his time for the third race

Use the quadratic function to predict f(x) if x equals 8. f(x) = 25x2 − 28x + 585