4(5x-20)= -20
20x-80= -20
+80 +80
____________
20x=60
_______
20
x=3
Answer: The required value of y is 19.
Step-by-step explanation: We are given to find the value of y in the solution to the following system of equations :

Comparing equations (i) and (ii), we get

From equation (i), we get

Thus, the required value of y is 19.
4/7 = y/5019....with y being yes votes
cross multiply
(7)(y) = (4)(5019)
7y = 20076
y = 20076/7
y = 2868 <=== yes votes
total of yes and no votes : 5019 + 2868 = 7887
1st year= 18000 x 0.85 = 15300
2nd year= 15300 x 0.85 = 13005
3rd year= 13005 x 0.85= 11054.25