Question 369049
"Joe has a collection of nickels and dimes that is worth $9.6" ___ 5n + 10d = 960 ___ 5n = 960 - 10d


"If the the number of dimes was tripled and the number of nickles was decreased by 31 the value would be $6.70
___ 5(n - 31) + 10(3d) = 670 ___ 5n - 155 + 30d = 670


substituting ___ (960 - 10d) - 155 + 30d = 670 ___ 20d = 670 - 805



it appears that the number of dimes is negative , which means something is amiss ...