Choice A doesn't work because it the $1 should be $7 instead.
Choice B doesn't work because it should be Elena spending $7 total on 3 notebooks and a $1 pen. The x is the amount per notebook.
Choice C does work. If x is the number of grapes Noah gives each friend, then 3x is the total amount Noah gives over. Then 3x+1 is the number of grapes total. That +1 at the end is the grape Noah eats. We end up with 3x+1 = 7 because Noah starts off with 7 grapes.
Choice D works also. The x is the number of hours for math, science and history each. So 3x is the combined time of those three classes. Add on 1 to get 3x+1 to represent all 7 hours, ie 3x+1 = 7.
Choice E does not work. If it was her spending $7 on 3 markers and a $1 pen, then it would work.

8 0

2 years ago

astra-53 [7]

Answer:

2+i times the square root of 7

4 0

3 years ago