If X & # 178; - ax + 2a-4 is a complete square, find the value of A

If X & # 178; - ax + 2a-4 is a complete square, find the value of A

If X & # 178; - ax + 2a-4 is a complete square,
Then, X & # 178; - ax + 2a-4
=(x-b)^2
-2b=-a b=a/2
2a-4=b^2
So, 2a-4 = a ^ 2 / 4
8a-16-a^2=0
a^2-8a+16=0
(a-4)^2=0
So, a = 4