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Question
How many quadratic equations can be formed using numbers from 0, 2, 4, 5 as coefficient if a coefficient can be repeated in an equation.
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Solution
Let the quadratic equation be
ax2 + bx + c = 0, a ≠ 0
| Coefficient | Values | Numbers of ways |
| a | 2, 4, 5 | 3 |
| b | 0, 2, 4, 5 | 4 |
| c | 0, 2, 4, 5 | 4 |
Required number = 3 × 4 × 4 = 48
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