v² + 10v + 16 = (v+8) (v + ?)
Distributing:
v² + 10v + 16 = v(v) + v(?) + 8(v) + 8(?)
v² + 10v + 16 = v² + (?v + 8v) + 8(?)
We need that:
10v = ?v + 8v
and
16 = 8(?)
From the first equation:
10v = ?v + 8v
10v - 8v = ?v
2v = ?v
2 = ?
From the second equation:
16 = 8(?)
16/8 = ?
2 = ?