Answer:
$780
Explanation:
The final price of an item can be calculated with the formula P = A(1-r), where P is the final price, A is the original amount, and r is the rate (as a decimal).
Using the given information, this gives you 670.80 = A(1-0.14).
Simplify the right side, then divide 670.80 by that number.
You can check by multiplying 780x0.14=109.20, and subtract that from 780.