Expain why this problem cannot be solved by subtracting 2/3- 1/3

lauren has 2/3 of a foot of ribbon. she cuts off 1/3 of an inch ribbon. how much ribbon does lauren have now

Asalesperson earns $320 per week plus 8% of her weekly sales. the expression representing her earnings is 320 + 0.08x. which of the following describes the sales necessary for the salesperson to earn at least $1000 in the one week?

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If g^-1(x) is the inverse of g (x) which statement must be true