Answer: it would take 40 text messages before you pay the same amount for both offers.
Step-by-step explanation:
Let x represent the number of messages that you send with either Verizon or AT&T
Let y represent the total amount paid for x messages using Verizon
Let z represent the total amount paid for x messages using AT&T
Verizon offers a text messaging plan for $9.99(999 cents), but you are charged 10 cents if you go over your allotted messages. This means that the total amount for x hours would be
y = 10x + 999
AT&T is offering the same messaging plan for $7.99(799 cents), but it costs 15 cents for every message over your limit. This means that the total amount for x hours would be
z = 15x + 799
To determine the number of messages before the amount for both offers becomes the same, we would equate y to z. It becomes
10x + 999 = 15x + 799
15x - 10x = 999 - 799
5x = 200
x = 40