12 I got it form Socratic
Answer:
2 hours
Step-by-step explanation:
If Thomas can paint 1/3 = 2/6 of the room in a hour and Brian can paint 1/6 of the room in an hour. Which means in an hour they can collectively paint 3/6 = 1/2 of the room. Now you need to find how long it would take then to paint 2/2 of the room. Knowing that 1/2+1/2 = 2/2, it would take them 2 hours to paint the room together
Answer:
r= 3
Explanation:
1. Write the division as a fraction
1/2r-3=3(4-3/2r)
2.Distribute the 3 through the paranthesis
1/2r-3=12-9/2r
3.Multiply both sides by 2
r-6=24-9r
4. Swap -6 and -9 together by changing their signs
r+9r= 24+6
5.Add them together
10r=30
6. Divide both sides by 10
r=10
Hope this helped :)