complete the square
isolate x terms
y=(x^2-14x)+53
take 1/2 of -14 and square it ((-7)^2=49
add plus and minus of that inside the parntehasees
y=(x^2-14x+49-49)+53
factor perfect suqrae
y=((x-7)^2-49)+53
get rid of parnthasees
y=(x-7)^2-49+53
y=(x-7)^2+4
C isi answer