The baby shark swims +3feet below sea level every passing day.
x= the number of days that passed
y= represents the deph the baby shark swims
y=3x
If the number of days that pased is 5 then
y=3*5=15ft
In five days, the baby shark will swin 15 feet below surface.
You can also solve this problem using cross multiplication
1day_____3feet
5days____x= (5*3)/1=15feet