Final answer:
The middle term in the expression (a+6)^2 is found through the binomial expansion and results in 12a.
Step-by-step explanation:
The middle term you asked about in the expression (a+6)^2 can be found by applying the binomial expansion. When you square a binomial expression, you use the pattern a^2 + 2ab + b^2. In this case, a is the variable a and b is the number 6. So, when you square (a+6), you get:
- a^2 (which is the first term squared),
- plus 2*(a)*6 (which is twice the product of the first term and the second term and represents the middle term),
- plus 6^2 (which is the second term squared).
Therefore, the middle term in the expression (a+6)^2 is 2*a*6 or simply 12a.