Two phone companies have a plan with the same monthly allowa

Two phone companies have a plan with the same monthly allowance on minutes, company A charges a monthly rate of $180 plus 75 cents per minute for each additional minute you go over the monthly allowance. Company B charges $230 plus 50 cents per minute for each additional minute you go over the monthly allowance. How many minutes would you have to go over in order for both bills to be the same amount?

Solution

company A equation can be written as

y = .75x + 180

company B equation can be written as

y = .50x + 230

where x is the number of minutes

in order for both bills to be same we set both equations equal to each other and solve for x

.75x + 180 = .50x + 230

subtracting .50x from both sides

.25x + 180 = 230

subtracting 180 from both sides

,25x = 50

x = 50/.25

x = 200

so 200 minutes you would have to go over for both bills to be same