Can somebody .. i have a test tomorrow and im trying to pass it

For 7., you have to add 3 to both sides to cancel out like terms, so you'll end up with:
x/8=10
Then cross multiply, you'll get x=80.
For 9., add 2n to both sides and subtract 2 from both sides to get 39=3n. Divide both sides by 3 to get n= 13. Hope this helps!