300,60,12,2.4 what is the difference

The graph below represents the number of dolphins in a dolphin sanctuary. select all the key features of this function.

To solve the system of equations below, pedro isolated the variable y in the first equation and then substituted it into the second equation. what was the resulting equation? { 5y=10x {x^2+y^2=36

Pls never taught i’m really confused and i rlly need