When handling problems of this nature make sure you setup the equations.
x = number of times they rent a boat.
Members
Cost = 105 + 9.50x
Non members because members don't have to pay the 105 we leave it out.
Cost = 14.75x
so now to determin when cost would be equal we set the two equations = to each other
105 + 9.50x = 14.75x
now solve for x
105 = 5.25x
20 = x
so they would have to rent 20 times to equal each other.
To start this, try to place it all together.
(x)+(x+2)+(x+4)=36
Then you start to combine so that it looks like this:
3x+6=36
I believe that is one of the choices. Do you need more explanation?
Look here in a square which is what I imagine that drawing is all the angles are 90 degrees. A rectangle would be knowing two angles is know all of them one way or another so fix your work and you should know the answer