Question 930446
Hint: the system of equations you need to solve is 


{{{system(4(L+W+H) = 52,L = 2W,H=W+1)}}}


You can do two substitutions to go from {{{4(L+W+H) = 52}}} to {{{4(2W+W+W+1) = 52}}}. Solve that for W and use that to find L and H.