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Find the roots of quadratic equation 15x2 - 28 = x |
Answer» Given 15x2 - 28 = x ⇒ 15x2 - x - 28 = 0 ⇒ 15x2 - (21x - 20x) - 28 = 0 ⇒ 15x2 - 21x + 20x - 28 = 0 ⇒ 3x (5x - 7) + 4(5x - 7) = 0 ⇒ (3x + 4) (5x - 7) = 0 ⇒ 3x + 4 = 0 or 5x - 7 = 0 ⇒ x = -4/3 or x = 7/5 Hence, the roots of the equation are -4/3 and 7/5. |
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