A school librarian can buy books at a 20% discount from the list price. One month she spent $72 for books. What was the list price value of the books?

Is the answer $90?

yes

0.8P = 72,

P = $90.

To find the list price value of the books, we can follow these steps:

1. Let's assume the list price of the books as "x" dollars.
2. The school librarian can buy books at a 20% discount, which means she pays 80% of the list price.
3. We can calculate the amount she paid as: 80% of x = $72.

Now, let's solve the equation to find the value of "x":

0.8x = $72

To isolate x, we divide both sides of the equation by 0.8:

x = $72 / 0.8

Calculating the right side of the equation:

x = $90

Therefore, the list price value of the books is $90, not $72.