Tavon has a gift card for $135 that looses $3 for each 30 day period it is not used. He has another gift card for $115 that looses $2.50 for each 30 day period it is not used.

Answer 1

If the question asks when they are worth the same amount, then here it is.

Call t a thirty day period.

135 - 3t = 115 - 2.5t

Add 3t to both sides. Subtract 115 from both sides.

20 = .5t

20/.5 = t

40 = t

In 40 30 day periods, 1200 days (a little less than 4 years), their value is the same.