Respuesta :

Answer:

Therefore, Peter is 21 years old.

Step-by-step explanation:

    [tex]\bf{ x+11=\dfrac{(x-13)^2}{2} \ \Longrightarrow \ 2x+22=x^2-26x+169 }[/tex]

          [tex]\bf{ 0=x^2-28x+147=(x-21)(x+7) }[/tex]