Question

What value of x makes this equation true?

2x+9-4x-x-12

Hint: You can either solve for x (isolate the variable), or you can plug each of the values below in for each x in the equation and simplify to see which answer makes both sides equal.

7

-21

-1

3

Answer 1

To solve the equation \( 2x + 9 - 4x - x - 12 = 0 \), we can first simplify the left side.

Combine like terms:
\[
2x - 4x - x + 9 - 12 = -3x - 3
\]

So, our equation simplifies to:
\[
-3x - 3 = 0
\]

Now, isolate \( x \):
\[
-3x = 3
\]
\[
x = -1
\]

Now, we can check if \( x = -1 \) satisfies the original equation:

Substituting \( x = -1 \) into \( 2x + 9 - 4x - x - 12 \):
\[
2(-1) + 9 - 4(-1) - (-1) - 12 = -2 + 9 + 4 + 1 - 12
\]
\[
= -2 + 9 + 4 + 1 - 12 = 0
\]

This is equal to 0, confirming that \( x = -1 \) satisfies the equation.

Thus, the value of \( x \) that makes the equation true is:
\[
\boxed{-1}
\]