She should buy at the second store due to the fact that you are getting 6 mora for the same price (if you were to buy 30$ worth from the first one)
The number is 18.
In order to find this, we need to take each side and turn them into mathematics statements.
Five times the sum of a number and 3.
5(x + 3)
3 times the difference of twice the number and 1
3(2x - 1)
Now that we have these, we can set them equal to each other and solve.
5(x + 3) = 3(2x - 1) ----> Distribute
5x + 15 = 6x - 3 -----> Subtract 5x from both sides
15 = x - 3 -----> Add 3 to both sides
18 = x
See the attached picture:
X represents 14 so the answer should be x=14
You will make 4 sales if you are making a sale between 3 and five because 4 is whats in between 3 and 5. If your are to compute you will make a sale of average 4 because the average of 3 and 4 is 5. Computed as 3+5/2=4.