Abraham brags, "my cell phone plan is the best! I pay just 25$ per month, and then $.10 per minute" Abbott quickly counters, "Well my cell phone plan is even better! I only pay $20 per month and then $.12 per minute." Who has the better cell phone plan?
+128448 Let x be the number of minutes that equalize the cost of both plans
So we have
25 + .10x = 20 + .12x subtract .10x, 20 from both sides
5 = .02 x
5 = (2 /100) x reduce the fraction
5 = (1/50) x multiply both sides by 50
250 = x = the number of minutes that equalize the cost of both plans
Comparing the slopes of .10 and .12.......the plan that costs $20 per month and 12 cents per minute is cheaper if the number of minutes < 250......after 250 minutes, the other plan is better
