Explanation
[tex](a+b)^2=a^2+2ab+b^2[/tex]Step 1
[tex]\begin{gathered} A=6(s+2)^2 \\ A=6(s^2+2\cdot2\cdot s+2^2) \\ A=6(s^2+4s+4) \end{gathered}[/tex]Step 2
apply the distributive property
[tex]\begin{gathered} A=6(s^2+4s+4) \\ A=6s^2+24s+24 \end{gathered}[/tex]I hope this helps you.