A group of high school students are volunteering for Habitat for Humanity during their summer break. They are putting the finishing touches on a house they builtWorking alone, Kendra can paint a certain room in 7 hours. Joe can paint the same room in 6 hours. Write an equation that can be used to find how long it will take them working together to paint the room. How many hours will it take them to paint the room? if necessary, round your answer to the nearest tenth.