What function should be graphed in order to solve the equation 9x - 6= -8 PLEASE can you explain step by step how you come up with the answer 9x+2 as the answer? How do you know and prove it? Thank you.

A)f(x)=17x-6
B)f(x)=9x-14
C)f(x)=9x+2
D)x-6

1 answer

To solve the equation \( 9x - 6 = -8 \), we first want to isolate \( x \). Here's how we can do it step by step:

Step 1: Add 6 to both sides

We start with: \[ 9x - 6 = -8 \] Adding 6 to both sides gives: \[ 9x - 6 + 6 = -8 + 6 \] This simplifies to: \[ 9x = -2 \]

Step 2: Divide by 9

Next, we divide both sides by 9: \[ x = \frac{-2}{9} \]

Finding the Corresponding Function

To find a function that corresponds to the original equation, we can rearrange the equation so that it is set to \( f(x) = 0 \).

The original equation rearranged is: \[ 9x - 6 + 8 = 0 \] This simplifies to: \[ 9x + 2 = 0 \] So, if we wanted to express this as a function, we can say: \[ f(x) = 9x + 2 \]

Match the Function to the Choices

From the choices given:

  • A) \( f(x) = 17x - 6 \)
  • B) \( f(x) = 9x - 14 \)
  • C) \( f(x) = 9x + 2 \)
  • D) \( f(x) = x - 6 \)

The correct choice is: C) \( f(x) = 9x + 2 \)

Verification

To verify that this function works for the equation \( 9x - 6 = -8 \), we can check if setting this function \( f(x) = 0 \) leads us back to the original equation.

If \( f(x) = 9x + 2 \), to find the \( x \) where \( f(x) = 0 \): \[ 9x + 2 = 0 \] Subtracting 2 from both sides: \[ 9x = -2 \] Dividing by 9: \[ x = \frac{-2}{9} \]

This is indeed the same \( x \) we found while solving the original equation. Therefore, the function \( f(x) = 9x + 2 \) is correct, confirming: C) \( f(x) = 9x + 2 \) as the answer.