Final answer:
The question relates to evaluating an algebraic expression with a function. The information provided is insufficient to determine the exact value of -8x + 20 for f(-1) or 5 - 2[f(-1)] without the specific definition of the function f(x). In an illustrative example, with an assumed value for f(-1), the process to find the expression's value is demonstrated.
Step-by-step explanation:
The task given involves evaluating an expression with a function f where f(-1) is part of a composite expression. To find the value of -8x + 20 for f(-1), one would typically replace x with -1 in the function's formula. However, since the question might be missing additional context or the complete function's definition, we cannot solve it directly. For 5 - 2[f(-1)], assuming we knew f(-1), we would double the value of f(-1), subtract it from 5, and obtain the result.
As a guiding example, let's say hypothetically that f(-1) = 3, in which case 5 - 2[f(-1)] would be 5 - 2[3], simplifying to 5 - 6, and resulting in -1.