1 7/24 is the correct answer I will show you how to get it if needed.
Step-by-step explanation:

its hard to determine without the known value of x, but the above would be the equation needed to solve it if you knew what x was
To find your answer you would divide 21 by 3 which would be 7, once you've got 7 you would multiply it by 9 which would give you the amount of old houses that there is which would be 63.
The fraction symbolizes division. Divide, buddy.
Answer:
you can use similar triangle to make known degrees in problems to make then easier to solve. With similar triangle, the angles are the same, but the scale is different. So by using this, one can solve both at the same time, and just just scale up the smaller one or scale down the larger, by the given/found scale.
Step-by-step explanation: