This is very simple, you can use tally marks to find the amount of birthdays. Then divide it by 100. Good luck !
Converting all to improper fractions
31/10s = 31/5
5×31s=31×10
155s = 310
s=310/155= 2
20/9=-4/5m
5×20=-4×9m
100=-36m
m=100/-36 = 72 28/36 = 72 7/9
-14/5=-7/2n
-14×2=5×-7n
-28=-35n
n =-28/-35
n=28/35
The slope is - 3/10
Y over x