Where the rest of the question?
The answer to your question is -10
Yes it is already simplified because there is nothing else that you are able to do to it.
Answer:
15%
Step-by-step explanation:
The first step is to find the loss
Cost price -selling price
37000-31450
= 5,550
The loss percent can be calculated as follows
= loss/cost price × 100
= 5550/37000 × 100
= 0.15×100
= 15%
Hence the loss percent is 15%
Let Benny's salary = $ K
But kenny earns 142% of Benny's Salary
So, Kenny's salary = 142%of K
Kenny's salary =K 
Kenny's salary = 1.42K
Kenny's income exceeds Benny's by =1.42K - K =$0.42 K
% by which Kenny's salary exceeds by Benny's =
% by which Kenny's salary exceeds by Benny's = 42%