Answer:
C
Step-by-step explanation:

Rounding to nearest thousand gives 76,000 mg of chlorine
(Y-Y1)/(X-X1)
(-9-(-29))/(7-15)
20/-8
-2 1/2
The slope is -2 1/2
Okay you have 2 sum unknow lets call them X+Y
so X+Y=33, 4X=108
Get X by it self then plug it in 4X=108
X=-Y+33
4(-y+33)= 108
-4y+132=108 Then subtract the 132
-4y=-24 Y=6 then to find X subtract 33-6=27
Y=6 X=27 if you check it works out
#1. A- the square would have the greatest perimeter.