What does the equation -355-n=-957 what does n equal?

When you want to find the value of a variable, isolate it. 
First, add 355 to both sides of the equation to get rid of the -355 on the left side of the equation. We get -n = -602. 
We're not done yet! We need to change the -n to +n, or just n. Multiply both sides by -1. We get n = 602.
n = 602.
Hope that helped you.

I'll say b) log(- that if not let me know what i can do

The answer is biodiversity resulting from new ancestors.