Proof by Contradiction

[isuckatmath123]

I was doing some studying for an upcoming test and I'm still struggling to wrap my head around the more complex questions that have more variables to them. such as... the file I attached. any help would be amazing as I'm stressing heaps!! thank u

 

[Dr.Peterson]

Since you didn't show any work or say where you are having trouble, let's just start at the beginning.

How would you begin a proof by contradiction? What do you propose assuming, that you hope will lead to a contradiction?