Answer:
A = 2, the number is 3221
Step-by-step explanation:
In order for the number to be divisible by 9, the sum of it's digit has to be divisible by 9.
In our case,
where k is an integer. the easiest way happens when k=1

Higher values of k will likely most work (with k=2 you get A to be a non-integer, which can't work since it's the digit of a number, and with higher values of K you're not getting a number in base 10.
Answer:
7.25
Step-by-step explanation:
Answer: 7 BATCHES
Step-by-step explanation: to produce one batch it takes 7/10 of oatmeal
Now the factory uses 4 9/10 batch of oatmeal
1=7/10 OATMEAL
X=4 9/10 OATMEAL
X=(7/10*1)/4 9/10
=4 9/10*10/7
=490/70
=7
Answer: Senior: $8, Child: 14
Step-by-step explanation:
3s + c = 38
3s + 2c = 52
c = 14
3s + 14 = 38
3s = 24
s = 8