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Question
Solve the following equation by the trial-and-error method: 4x = 28
Solution
4x = 28
We try several values of x until we get the L.H.S. equal to the R.H.S.
| x | L.H.S. | R.H.S. | Is L.H.S. = R.H.S.? |
| 1 | 4 × 1 = 4 | 28 | No |
| 2 | 4 × 2 = 8 | 28 | No |
| 3 | 4 × 3 = 12 | 28 | No |
| 4 | 4 × 4 = 16 | 28 | No |
| 5 | 4 × 5 = 20 | 28 | No |
| 6 | 4 × 6 = 24 | 28 | No |
| 7 | 4 × 7 = 28 | 28 | Yes |
∴ x = 7
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