A function follows the rule y = -75 - 5x. When the function's output is 25, the equation is 25 = -75 - 5x.

Question

What is the function input when the output is 25?

20
-10
-20
10

Answer 1

To find the function input \( x \) when the output \( y \) is 25, we can set up the equation based on the given function:

\[ 25 = -75 - 5x \]

Now, we'll solve for \( x \).

1. Add 75 to both sides of the equation:

\[ 25 + 75 = -5x \]

This simplifies to:

\[ 100 = -5x \]

2. Next, divide both sides by -5:

\[ x = \frac{100}{-5} \]

This simplifies to:

\[ x = -20 \]

So, the function input when the output is 25 is \( \boxed{-20} \).