Which equation is true when x = 4?
Understand the Problem
The question is asking which of the provided equations is true when substituting x with 4. The process involves evaluating each equation by replacing x with 4 and checking if the equation holds true.
Answer
The equation that is true when $x = 4$ is $5x - 2 = 18$.
Answer for screen readers
The correct equation is $5x - 2 = 18$.
Steps to Solve
- Substituting for equation F
Substituting $x = 4$ into the equation $3x + 4 = 8$:
$$ 3(4) + 4 = 12 + 4 = 16 \quad (\text{Not true}) $$
- Substituting for equation G
Substituting $x = 4$ into the equation $5x - 2 = 18$:
$$ 5(4) - 2 = 20 - 2 = 18 \quad (\text{True}) $$
- Substituting for equation H
Substituting $x = 4$ into the equation $2x + 8 = 40$:
$$ 2(4) + 8 = 8 + 8 = 16 \quad (\text{Not true}) $$
- Substituting for equation J
Substituting $x = 4$ into the equation $4x + 4 = 12$:
$$ 4(4) + 4 = 16 + 4 = 20 \quad (\text{Not true}) $$
The correct equation is $5x - 2 = 18$.
More Information
When substituting $x = 4$ into each equation, only equation G simplifies correctly to equal 18, confirming it is valid. This process demonstrates how to evaluate linear equations by substitution.
Tips
- Forgetting to multiply before adding or subtracting when working with the order of operations.
- Not double-checking calculations to ensure accuracy.