For this case, we must find the quotient of
divided by
, to verify if Tina was correct.
So:

So, Tina was wrong, she had to divide by 3x.
Answer:
Option B
If you want to make 10, you can take 3 from the 13 and add it to the 7. You will then have 10+10 which equals 20.
Any arithmetic sequence can be expressed as:
a(n)=a+d(n-1), a=initial term, d=common difference, n=term number
In this case a=5, and d=-2 so
a(n)=5-2(n-1) which can be simplified...
a(n)=5-2n+2
a(n)=7-2n
The domain is restricted to integers from 1 to +oo.