Answer:
Step-by-step explanation:
let x be the number of 30 day periods
135 - 3x = 115 - 2.50x
135 - 115 = -2.50x + 3x
20 = 0.50x
20 / 0.50 = x
40 = x
135 - 3(40) = 135 - 120 = 15
115 - 2.50(40) = 115 - 100 = 15
they will each be $ 15
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so there are 40 thirty day periods.....40 * 30 = 1200 days