For the function For the function f (x) = 2|5x+7|-1, evaluate f (-4).

f ( - 4) = 25

Step-by-step explanation:

Note the absolute value function | a | always returns a positive value, that is

| - a | = | a | = a

Given

f (x) = 2 | 5x + 7 | - 1

To evaluate f ( - 4) substitute x = - 4 into f (x)

f ( - 4) = 2 | 5 ( - 4) + 7 | - 1 = 2 | - 20 + 7 | - 1 = 2 | - 13 | - 1 = (2 * 13) - 1 = 26 - 1 = 25

f (-4) = 25