Final answer:
Given (2ˣ = 5), the expression (2¹x - 4) simplifies to (5²), which equals 25. Option b is the correct answer.
Step-by-step explanation:
The question deals with exponents and powers. Given that (2ˣ = 5), we want to find the value of (2¹x - 4). We can use the properties of exponents to solve this problem. Since 2¹x is the same as (2ˣ)¹, we can substitute the value of 2ˣ, which is 5, into the expression. So it becomes (5¹ - 4), which simplifies to 5² or 25. Thus, option b, which is (5²), is the correct answer.