Question

A cell phone company offers two plans for unlimited calling. The first plan has a monthly charge of $25 and 8.08 per text message. The second plan has a monthly charge of
$20 and $.12 per text message. For how many tect messages would the two plans have an equal cost? (What is the solution to this system? X represents the #of text
messages and represents the total costs)

• 66
• 175
• 125
• they will never cross

Answer 1

The answer is 125 messages.
Firstly the best thing to do is create two different equations.
1. y=25+.08x
2. y=20+.12x
Then you plug into Desmos and see at what point they cross. They cross at (125, 35).
Therefore for 125 text messages would cost 35$ for each plan.