Dave did 3 more dives than he did laps and Crystal did 4 more laps than she did dives
(6,-5)
5x-6(0)=30
5x=30
5x/5= 30/5
x=6
5(0)-6y=30
-6y=30
-6y/-6=30/-6
y= -5
I think 28 (2x16) = 32 -4 + 28
For an exponential function the y-intercept is the "initial value" (not the common ratio).

will always be 2. if that's what you need
note that

because anything to the power of zero equals 0 (mathematically it's deciding something by itself)