Question 1: I'm actually not sure which term you ment exactly, so I calculated the solution for three possible variations of your term, depending on how one sets the brackets.
To calculate an ordered pay just set x or y to some value, insert it into the equation and you get the solution for the other variable. In these calculations I always picked x so values would get eliminated or as close to 0 as possible to make it easier.
variation 1 of term: y=(5^4)*(x-3) insert x=3 y=(5^4)*(3-3)==(5^4)*0=0 pair: (3,0)
variation 2 of term: y=(5^4)*x-3 insert x=0: y=(5^4)*0-3=0-3=-3 pair: (0,-3)
variation 3 of term: y=5^(4*x-3) insert x=1: y=5^(4*1-3)=5^1=5 pair: (1,5)
question 2: 2y=-5x-4 just insert the pairs as (x,y) into the equation:
