Consider 8x2 - 48x = -104. write the equation so that a = 1

In order to re-write the quadratic equation s/t a=1, we proceed as follows; The general quadratic formula is:
y=a(x-h)^2+k where (h,k) is the vertex;
hence;
8x^2-48x=-104
dividing through by 8 we get:
x^2-6x=-13i
Using completing square method;
c=(b/2)^2
c=(-6/2)^2=9
adding 9 on both sides of equation i we get:
x^2-6x+9=-13+9
(x-3)^2=-4
this can be written as:
y=(x-3)^2+4
where:
a=1
h=3
k=4