Final answer:
The value of n in the given expression cannot be derived from the provided information. To understand related concepts, when multiplying powers with the same base, add the exponents. Sequences equalling n^2 can be manipulated to show their pattern.
Step-by-step explanation:
The value of n in the expression 20 × 3 × 5^a. 2^3 × 3^4 × 5^4 × 7^b. 2 × 5^u is not provided, and cannot be determined directly from the information given. However, we can analyze expressions with similar structures. For example, when multiplying exponentiated quantities, remember that the exponents of like bases are added. In the case of (5^3)^4, this would equate to 5^(3×4), which is 5^12. This concept can also be applied for similar calculations, using proper mathematical rules and ensuring that answers are expressed in scientific notation where needed. When dealing with sequences, if an expression is said to equal n^2, manipulations can be performed to show that this is indeed true. Taking terms from one end of the sequence and adjusting others accordingly often facilitates understanding the underlying patterns.