Final answer:
To find f(-5) and f(7), use the corresponding parts of the piecewise function. For f(-5), we use 1 - 4x and get 21. For f(7), assuming the function is similar for x > 1, we might use 4x and get 28, but this is speculative due to the typo.
Step-by-step explanation:
To find f(-5) and f(7) using the piecewise-defined function f(x), we need to determine which part of the function to use for each value of x.
According to the given function, for x less than or equal to 1, we use f(x) = 1 - 4x. And for x greater than or equal to 1, provided there is a typo in the function for f(7), we would normally expect a function piece that handles values of x greater than 1. However, since the value provided for when x >= 7 seems to be either a typo or incomplete, we'll assume there is a similar rule for values of x greater than 1 but not equal to 7.
For f(-5):
x = -5 <= 1, so we use the first part of the piecewise function.
f(-5) = 1 - 4(-5) = 1 + 20 = 21
For f(7):
Assuming a typical piecewise function scenario for values where x > 1 and not handling the exact value of 7 due to the typo:
f(7) would be, say, 4x if we were following a similar rule for higher values of x, thus:
f(7) = 4(7) = 28