Add the similar variables (think apple+apple), in this case, we would add 2q+4q.
Well, what is 4 apples plus 2 apples? 6 apples, simply, 6q
Since 3 is without a variable, we will leave it as is
Therefore, 2q+4q+3= 6q+3
Hope this helped :)
Not exactly sure but I think it's false hope this helps
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%
C. 8^4x
64^2x = 4096x
8^4x= 4096x