The answer is option C. Both Friedrich and Jung have the most debt. Hope I could help! :D
Well first you have to add common like terms in this case 2r and -6r to get -4r now your equation is -4r+8=40, now subtract 8 from both sides to leave r by itself and get -4r=32, now divide both sides by -4 to get r=-8
Hope this helps
For this case we have the following expression:

We clear the value of the variable "g", for this:
We multiply by 4 on both sides of the equation:

We divide by 3 on both sides of the equation:

We simplify:

Answer:
