Respuesta :

manissaha129

Answer:

[tex] {x}^{2} - 8x + \boxed{16} \\ = {x}^{2} - 2 \times 4 \times x + {4}^{2} \\ = {(x - 4)}^{2} [/tex]

So, 16 should be added to the expression to make it a complete square.

Formula used : (a-b)²=a²-2ab+b²