Question

Lillian and Isabella went shopping for school supplies. Lillian found her favorite notebook on sale so she bought three of the exact same notebook. Isabella also wanted a notebook. She bought one of the same notebooks that Lillian bought. Both girls started shopping with the same amount of money. If Lillian spent all of her money and Isabella had $5 left, how much money did each girl have when she arrived at the store? please show your work/steps​

Answer 1

Answer:

Each girl had $7.50 when they arrived.

Step-by-step explanation:

We have to figure out what c (cost of each notebook) is first before we find out how much money each girl had. We also know they have the same money, so both sides are connected. The equation should be: 3x = x + 5.

3x = x + 5

First, subtract x from both sides. This cancels out the addition by x.

3x - x = 5

Now, subtract x from 3x. This equals 2x.

2x = 5

To cancel out the multiplication by 2, divide both sides by 2.

x = 5/2

Lastly, divide 5 by 2 to get 2.5.

x = 2.5

Substitute x for 2.5 in the earlier equation (3x = x + 5)

3(2.5) = 2.5 + 5

First, multiply 3 by 2.5 to get 7.5.

7.5 = 2.5 + 5

Add 2.5 to 5 to get 7.5.

7.5 = 7.5

Both sides are equal so we have our answer. So, both girls had $7.50 when they arrived at the store.