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Question
Solve the following equation by factorization
x2– 4x – 12 = 0,when x∈N
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Solution
x2 – 4x – 12 = 0
⇒ x2 – 6x + 2x – 12 = 0
⇒ x (x – 6) + 2 (x – 6) = 0
⇒ (x – 6) (x + 2) = 0
Either x – 6 = 0, then x = 6
or x + 2 = 0, then x = -2
But -2 is not a natural number
∴ x = 6.
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