To express \( 7^{15} \) in an expanded form, you can rewrite it using repeated multiplication:
\[ 7^{15} = 7 \times 7 \times 7 \times 7 \times 7 \times 7 \times 7 \times 7 \times 7 \times 7 \times 7 \times 7 \times 7 \times 7 \times 7 \]
Alternatively, it can also be expressed in terms of factors of smaller powers of 7. For example:
\[ 7^{15} = (7^5)^3 \] This is equivalent to:
\[ (7 \times 7 \times 7 \times 7 \times 7)^3 \]
You can choose which form you prefer based on your needs. If you seek numeric values, \( 7^{15} \) calculates to 4747561509943.
If you need the expression in a different manner, such as a binomial expansion or other forms, please let me know!