Answer:
The missing monomial should be [tex]3b[/tex].
Step-by-step explanation:
Given that,
[tex]( + 2a)^2 = + 12ab + 4[/tex]
Let the missing monomial is x.
[tex]( x+ 2a)^2 = x^2+ 12ab + 4a^2\\\\( x+ 2a)^2=(3b)^2+ 2(2a)(3b) + (2a)^2\\\\So,\\\\( 3b+ 2a)^2=(3b)^2+ 2(2a)(3b) + (2a)^2[/tex]
So, the missing monomial should be [tex]3b[/tex].
