Question

The height of Tower A is 720 feet more than Tower B. The two towers have a combined height of 1,982 feet. What are the heights of each​ tower?

Answer 1

Okay so. 

We have two basic equations 

Tower A+ B+720    A is 720ft taller than B. 
Tower A+B= 1982     Combined height is 1982ft

Replace A with B+720 in 2nd equation and solve for B 

B+720+B=1982   Combine like terms 
2B+720=1982     Subtract 720 from both sides
2B=1262              Divide both sides by 2
B=1262/2 
B= 631ft 

We know that A=B+720 so you simply need to do that addition to have the height of both towers.