Question 8985
It looks right to me.  To finish, just solve the equation:
3b - b = 50  


Remember that b = 1b, so 3b - 1b = 2b
2b = 50
b= 25 feet= height of the building
3b = 75 feet = height of the tower.


Check:  You said that the tower is supposed to be 50 feet taller than the building, which indeed it is!!  So you got it right, and it checks!  Nice work!!


R^2 at SCC