Can you read and give me the equation I need? NO SOLVING REQUIRED, it would be the biggest help:)))

Jordan is a manager of a car dealership. He has two professional car washers, Matthew and Arianna, to clean the entire lot of cars. Matthew can wash all the cars in 14 hours. Arianna can wash all the cars in 11 hours. Jordan wants to know how long it will take them to wash all the cars in the lot if they work together.

Write an equation for the time it will take Matthew and Arianna to wash all the cars together