A store is offering a 11% discount on all items. Write an equation relating the final price

A store is offering a 11% discount on all items. Write an equation relating the final price

11% discount means we pay 100% - 11% = 89% of the full price. Since 89% as a decimal is 0.89. With a final price f and an original price p, we have:
F = 0.89p