Expand (x+2)^2

One day, a teacher asked students the following question in a test:

Expand (x+2)^2.

A student gave the following answer:

(x+2)^2
= (x_+_2)^2
= (x_____+_____2)_^_2
= (x__________+__________2)__^__2

note: _ means space; ^ means `to the power of'