Question

Tree pruning company A charges a one-time $100 equipment fee and charges $50 for each tree that it prunes. Tree pruning company B charges a one-time $80 equipment fee and charges $60 for each tree that it prunes.
Let the variable t represent the number of trees pruned and let the variable c represent the cost. For how many pruned trees will the cost be the same for both companies?

Which system of equations can be used to solve this problem?

{c=50+100tc=60+80t

{c=150tc=140t

{c=100−50tc=80−60t

{c=100+50tc=80+60t

Answer 1

The total cost that a customer should incur in its dealings with company A should be, 
                              c = 50t + 100
For company B
                              c = 60t + 80
Equating these two charges
                               c = 50t + 100 = 60t + 80
Thus, the answer is the fourth choice. 

Answer 2

the answer is

{c=100+50tc=80+60t

hope this helps