Wade can paint a certain room in 7 hours. Rhonda can paint the same room in 5 hours. How long will it take them working together to paint the room? Round your answer to the nearest hundredth if necessary.PLEASE come up with a rational expression to solve this problem. 

Wade can paint a room in 7hr. So in 1 hour she can paint 1/7 of roomSimilarly Rhonda can paint 1/5 of room in 1 hourLet x be the number of hour required if they work together1/7 + 1/5  = 1/x=> (5+ 7)/35 = 1/xx= 35/12= 2.91i.e around 3hrs will be required to paint the room together