For number 8, to solve for x you have to isolate it by dividing both sides of the equation by b. This will give you x=c/b. (Always see if you can do addition/subtraction so you don't get confused and then do multiplication/division. In this case you didn't need to add or subtract anything so you were able to just divide).
For number 9, again you have to isolate the variable p. Start be subtracting kn from both sides of the equation. The operation between m and p is multiplication. The opposite of this is division so divide both sides of the equation by m. Your answer should be p=(q-kn)/m.
For number 10, you're trying to isolate r so start by subtracting b. Now divide both sides by the b next to the r. Your answer should be r=(a-b)/b.
For number 11, you want t by itself so start by subtracting the p that's by itself. Now divide pr from both sides. Your answer should be t=(A-p)/pr.
For number 12, you want y by itself. All you have to do for this one is add b/m to the other side of the equation. Your answer should be y=x+(b/m).
Finally for number 13, you want to isolate p by multiplying both sides of the equation by q. Your answer should be p=q(m/n).
Let me know if you have any questions and I hope this helped!
