so basically I need help on this questions part a and part B$,$ especially on part B$,$ where when you look at the force, and you see the little triangle with the numbers three, four, five. Knowing moment is forced times distance and knowing that which sign should I use basically is it a positive this is a negative because I thought when Force is pointing down to the right that the Y axis would be negative and the X axis would've been positive but when I checked in the back of the book, it's saying that it's that the three over$5$ is positive and four over$5$ is negative so I want to know the reason why that is$.$ I don't know if I explained it well but if you can just do the problems and explain the reasoning to each of them and explaining why this is positive or this is negative.. Maybe I'll have a better understanding of why they are what they.