3 GBs per month because you have to take 30-21 (the monthly cost of the phone)=9 and each GB is $3 a month so 9 divided by 3= 3
What grade are you in I can try to help but this looks difficult can you try to explain it for me
So first write out the expression:

take two 10's from the top to cancel with the two 10's on the bottom.
3.9/1.3 is 3.
The answer is 3*10^3
Hello you answer will be...... -x+4
let me know if I’m right
Hope the answer helps you!!!
:)