Answer:
[tex]\large\boxed{v^2+8v+4^2=v^2+8v+16=(v+4)^2}[/tex]
Step-by-step explanation:
Use
[tex](a+b)^2=a^2+2ab+b^2[/tex]
[tex]v^2+8v=v^2+2(v)(4)\qquad\text{add}\ 4^2\ \text{to both sides}\\\\v^2+8v+4^2=v^2+2(v)(4)+4^2\\\\v^2+8v+16=v^2+2(v)(4)+4^2[/tex]