Answer:
in an equation ax^2+bx+c to complete the square it turns to
a(x+d)^2+e where d=b/2a and e=c-b^2/4a
example:x^2+4x+1=0
complete the square:
d=b/2a=4/2(1)=2
e=c-b^2/4a=1-4^2/4(1)
e=1-16/4=-3
a(x+d)^2+e
1(x+2)^2-3=0
check if it is rigt: (x+2)^2=x^2+4x+4
x^2+4x+4-3=
x^2+4x+1 it is correct
