1. Balance after 1 year with simple interest= 600 + (2.5 x 12) = 600 + 30 = $630
2. Balance after 1 year with compounded interest = P ( 1 + 

= 600 ( 1 + 
= 600 (1.0511) = $630.66 = approx. $630
750+20(30)=1350
Or do you need to explain it?
512=2w^2 is the best answer
Yes because the perimeter of the bulletin is 23 feet. this is because to find perimeter you use 2(L)+2(W).