Yolanda purchased a prepaid phone card for $25 . long distance calls cost 17 cents a minute using this card. yolanda used her card only once to make a long distance call. if the remaining credit on her card is $17.35 , how many minutes did her call last?

Step-by-step explanation:

Part A:  Substituting 5 for x in 4x − 1 ≤ 19 yields 4(5) - 1 ≤ 19, which is true.  Read, "19 is less than or equal to 19," which is obviously correct.

However, 4x − 1 < 19 reads "19 < 19," which is false.

Part B:  I would simply solve 5x + 2 = 47 for x.  Subtracting 2 from both sides, we get 5x = 45, so x = 9 is the one and only solution (makes the equation true).