Final answer:
To calculate 109², we use (a+b)² = a² + 2ab + b² with a = 100 and b = 9, resulting in 10000 + 1800 + 81, which simplifies to 11881.
Step-by-step explanation:
To calculate 109² using the polynomial identity (a+b)² = a² + 2ab + b², let's identify a and b in the number 109. We can break 109 into 100 + 9, which means a = 100 and b = 9. Thus, we apply the identity:
a² = 100² = 10000
2ab = 2 × 100 × 9 = 1800
b² = 9² = 81
Putting it all together, we get:
(100+9)² = 10000 + 1800 + 81.
After adding these together, the simplified result is:
11881
Therefore, 109² is equal to 11881.