Answer:

Step-by-step explanation:
10a + 9b = 3c
Subtract 9b to isolate the variable a.
10a = 3c - 9b
Now we need a singular a, so divide equation by 10.

So that's how you do it.
11
66=11×6
121=11×11
132=11×12
Katelyn because there are 3 feet in 1 yard therefore, Dave is 2616 feet away from school.
5 I guess I don't know if it's the right answer