Answer:
[tex]y = {x}^{2} - 8x + 7 \\ a = 1 \: and \: b = - 8 \\ the \: line \: of \: symmetry \: \\ x = \frac{ - b}{2a} = \frac{8}{2} \\ x = 4(line \: of \: symmetry) \\ y = {4}^{2} - 8(4) + 7 \\ = 16 + 32 + 7 = y = 55 \\ vertix \: is \: (4 ,55) \\ y = {0}^{2} - 8(0) + 7 \\ y = 7 \\ 0 = {x}^{2} - 8x + 7 \\ (x - 7)(x - 1) = 0[/tex]
