Step-by-step explanation:
ax^2+bx+c=0
a=leading term
ok so if the leading term is positive then opens up and has a min
if leading term is negative then opens down and has a max
leading term is positive
1x^2+8x
it has a min
to complete the square, move c aside take 1/2 of b and square it
b=8
8/2=4
4^2=16
now add that to both sides
x^2+8x+16+6=0+16
factor perfect square
(x+4)^2+6=16
subtract 6
(x+4)^2=10
subtract 10
(x+4)^2-10=0
vertex aka min or max is (h,k) when ou have
y=a(x-h)+k
h=-4
k=-10
