The equation for the table is f(x)=3x+1 so I don’t know for a but for b it would be f(x) because 1 is greater than 5.
180-2(55)-x=0
180-110-x=0
70-x=0
-x=-70
x=70°
If my calculations are correct , only 26 stacks of folders will only hold 7 folders evenly .. leaving 1 pile with 9 folders because 26*7= 182 & 184-182 = 2 . 7+2=9