Answer:
[tex] { \boxed{(x - 3)}}^{2} = \boxed{16}[/tex]
Step-by-step explanation:
[tex] {x}^{2} + 2x - 7 = 8x \\ \\ {x}^{2} + 2x - 8x = 7 \\ \\ {x}^{2} - 6x = 7 \\ \\ {x}^{2} - 6x + {3}^{2} = {3}^{2} + 7 \\ \\ {(x - 3)}^{2} = 9 + 7 \\ \\ { \boxed{(x - 3)}}^{2} = \boxed{16}[/tex]
