Which of the following equation has a solution of -7?

4x - 23 = 5

5x + 11 = -24

-3x - 8 = -29

-x + 3 = -4

1 answer

Let's check each equation by substituting \( x = -7 \) into them.

  1. For the equation \( 4x - 23 = 5 \): \[ 4(-7) - 23 = -28 - 23 = -51 \quad \text{(not equal to 5)} \]

  2. For the equation \( 5x + 11 = -24 \): \[ 5(-7) + 11 = -35 + 11 = -24 \quad \text{(equal to -24)} \]

  3. For the equation \( -3x - 8 = -29 \): \[ -3(-7) - 8 = 21 - 8 = 13 \quad \text{(not equal to -29)} \]

  4. For the equation \( -x + 3 = -4 \): \[ -(-7) + 3 = 7 + 3 = 10 \quad \text{(not equal to -4)} \]

The only equation that has the solution of \( x = -7 \) is:

\( 5x + 11 = -24 \).