Answer
a) For the plan to cost the same each month, you have to send or receive 100 text messages.
b) For 50 messages, plan A would be better choise.
Work Step by Step
let x be the amount of text messages, y= total money one has to pay
According to the problem, we have two equations:
Plan one: y=40+0.2x
Plan two: y=60
a) 40+0.2x=60 => 0.2x=20=>x=100
b) Plane one: y=40+0.2(50)=>50
Plane two: 60
=> Plane one would be better choice because it is cheaper than plan two $10 for 50 messages.
