Answer:
115 - 90 = 25
Step-by-step explanation:
115 - 90, which is equal to 25, is less than or equal to x!
Boy that math stuff will kill a cracker
from 2007 to 2012 is only 5 years, so we can see this as a compound interest with a rate of 1.2% per annum for 5 years, so
David's : y = 12,350 - (240x)
Amanda's : y = 12,350 + (240x)
David's equation is correct, because their spending will be multiplied by the number of months and then subtracted from their savings