To check the solution of the quadratic equation \((2x−7)(x+9) = 0\) by substitution and evaluating for the given values, we'll follow the steps below for each value in the table.
Checking each value
-
When \(x = 0\):
- Substituted: \[ (2(0)−7)((0+9)) = (−7)(9) \]
- Evaluate:
- Step 1: \((−7)(9) = -63\)
- Step 2: Check if \(-63 = 0\)?
- Conclusion: False statement.
-
When \(x = 3\):
- Substituted: \[ (2(3)−7)((3+9)) = (6−7)(12) \]
- Evaluate:
- Step 1: \( (−1)(12) = -12 \)
- Step 2: Check if \(-12 = 0\)?
- Conclusion: False statement.
-
When \(x = -9\):
- Substituted: \[ (2(−9)−7)((−9+9)) = (−18−7)(0) \]
- Evaluate:
- Step 1: \((−25)(0) = 0\)
- Step 2: Check if \(0 = 0\)?
- Conclusion: True statement.
-
When \(x = 9\):
- Substituted: \[ (2(9)−7)((9+9)) = (18−7)(18) \]
- Evaluate:
- Step 1: \( (11)(18) = 198 \)
- Step 2: Check if \(198 = 0\)?
- Conclusion: False statement.
Summary of the evaluations:
| Value | Substituted | Evaluate: Step 1 | Step 2 | True or False Statement? | |-------|-------------|-------------------|---------|--------------------------| | 0 | \((−7)(9)\) | \(-63\) | \(-63 = 0\)? | False | | 3 | \((−1)(12)\) | \(-12\) | \(-12 = 0\)? | False | | −9 | \((−25)(0)\) | \(0\) | \(0 = 0\)? | True | | 9 | \((11)(18)\) | \(198\) | \(198 = 0\)? | False |
From the table, the only value that satisfies the equation is \(x = -9\).