I think that is 1/2 the b term (1/2*22 and that squared) so the term to be added would be 11^2 = 121.
x^2 + 22x + 121 = (x+11)(x+11)
1) wat term should be added to x squared+22x, so tat the result is a perfect square trrinomial
2 answers
(x + a)(x + a)
=x^2 + 2ax + a^2
In the problem,
2ax=22x
2a=22
a=11
substituting back
(x + 11)(x + 11)
x^2 + 22x + 121
=x^2 + 2ax + a^2
In the problem,
2ax=22x
2a=22
a=11
substituting back
(x + 11)(x + 11)
x^2 + 22x + 121