I WILL GIVE 30 POINTS TO THOSE WHO ANSWER THIS QUESTION RIGHT

Answer:
11
Step-by-step explanation:
Givens:
AD = 8
AC = 4y - 28
y = ?
First we can see that AD and DC are equal.
-note AD and AC are not equal
But 2 times the length of AD should give you AC so.....
2 x length of AD = 16 = AC
We can use the equation:
16 = 4y - 28
Solve for y
16 + 28 = 4y
44 = 4y
y = 11
Therefore value of y is 11.