Answer:
[tex]B. 4x^2+20x+25[/tex]
Step-by-step explanation:
The length of the side:
[tex]2x+5[/tex]
In a square all sides have the same length.
And the area of a square is given by the formula:
[tex]Area=(length)^2[/tex]
so, substituting that the length is [tex]2x+5[/tex]
[tex]Area=(2x+5)^2[/tex]
and we solve this squared binomial with the formula:
[tex](a+b)^2=a^2+2ab+b^2[/tex]
in this case [tex]a=2x[/tex] and [tex]b=5[/tex]
thus, we get:
[tex]Area= (2x)^2+2(2x)(5)+(5)^2[/tex]
and solving:
[tex]Area=4x^2+20x+25[/tex]
which is option B.