25 POINTS AND BRAINLIEST

17. A group of college students is volunteering for Help the Homeless during their spring break. They are putting the finishing touches on a house they built. Working alone, Irina can paint a certain room in 9 hours. Paulo can paint the same room in 8 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 hundredth.

Irina can paint 1/9 of a room in 1 hour since she can paint a room in 9 hours. 1/9x, where x is the number of hours she works and 1/9 of a room per hour is her speed, would be her part of the calculation.

Paulo can paint 1/8 of a room in 1 hour since he can paint an entire room in 8 hours. 1/8x, where x is the number of hours he works and 1/8 of a room per hour is his speed, would be his part of the equation.

1/9x + 1/8x = 1 (Irina's portion of the room plus Paulo's portion of the room equals one complete room) would be the equation.

Look for a denominator that has the same value as the numerator. Both 9 and 8 split evenly into 72 as the initial number. We multiply the top of 1/9 by 8 to convert the fraction and get 8/72x because 9*8 = 72. We multiply the top of 1/8 by 9 to convert the fraction and get 9/72x because 8*9 = 72. We have 8/72x+9/72x=1 currently.

17/72x=1

÷ both sides by 17/72:

17/72x ÷ 17/72 = 1÷17/72

∴ x=1/1 * 72/17

∴ x=72/17= 4.24