Which situation CANNOT be represented by this equation? 4x+7=31Options are A: Taliba has $31 to order phone cases online. She buys 4 phone cases and pays a $7 shipping charge. What is x, the cost of each phone case?B. Taliba is ordering phone cases that cost $4 each online. There is also a $7 shipping charge. If she has $31 to spend, how many phone cases, x, can she buy?C. Taliba has $31 to order phone cases online. Each phone case costs $7, and there is a $4 shipping charge. How many phone cases, x, can Taliba buy?

the correct answer to your question is going to be option C. if we look at the equation 4x + 7 = 31, we can see that 4x stands for a number that changed depending on how much of something x can be. the 7 in the equation stands for something doesnt change depending upon variables how much or how little x will be. knowing this, if we look at option C we read that each phone case cost $7 while $4 is how much it costs to ship. since this problem is about how many $4 phone cases Taliba can get, C would incorrect because they say that $7 is the post of each phone case. 
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