13. The words are telling you
.. HT +TS = HM +MS +2
.. (2x +1) +(x) = (x +1) +(x +2) +2
.. 3x +1 = 2x +5 . . . . . . . . . . . . . . collect terms
.. x = 4 . . . . . . . . . . . . . . . . . . . . . add -2x-1
HT +TS = 3x +1 = 3*4 +1 = 13 miles
The route via the theater is 13 miles.
Via the mall, the route is 11 miles.
14. Solve this the way you would any 2-step linear equation. Subtract terms that don't have h, and divide by the coefficient of h.
S = 2πr^2 +2πrh
S -2πr^2 = 2πrh
(S -2πr^2)/(2πr) = h
If you like, you can rearrange this to
.. h = (S/(2πr)) -r
