Hi there! The answer is x = 1
[tex] {x}^{2}  - 8x + 7 = 0[/tex]
[tex](x - 7)(x - 1)[/tex]
Rule AB = 0, gives A = 0 or B = 0
[tex]x - 7 = 0 \:  \: or \:  \: x - 1 = 0 \\ x = 7 \:  \:  \:  \:   \:  \:  \:  \:  \: or \:  \: x   = 1[/tex]
Therefore, the smallest of both roots is x = 1.