Answer:
the total she earns with "d" hours of dog walking and "b" hours of babysitting is given by: 8 d + 12 b
Explanation:
If we use "d" to represent the number of hours that Susan walks the dog, and we define "b" as the number of hours she babysits, then the expression that represents the amount she earns by walking the dog is: $8 times d = 8 d
Similarly, the amount she earns by babysitting is $12 times b = 12 b
Then the total she earns with "d" hours of dog walking and "b" hours of babysitting is: 8 d + 12 b