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Find the roots of quadratic equations  \(\cfrac{4}{x}-3\) = \(\cfrac{5}{2x+3}\),x ≠ 0, - \(\cfrac{3}{2}\)

Answer»

 \(\cfrac{4}{x}-3\) = \(\cfrac{5}{2x+3}\),x ≠ 0, - \(\cfrac{3}{2}\)

⇒ \(\cfrac{4}{x}-\)\(\cfrac{5}{2x+3}\) = 3

⇒ \(\cfrac{8x + 12-5x}{x(2x+3)}\) = 3

⇒ \(\cfrac{3x+12}{2x^2+3x}\)= 3

⇒  \(\cfrac{x+4}{2x^2+3x}\) = 1

⇒  2x2 + 3x = x + 4   (cross multiplication)

⇒ 2x2 + 2x - 4 = 0

⇒ x2 + x - 2 = 0

⇒ x2 + 2x - x - 2 = 0

⇒ x(x + 2) - 1(x + 2) = 0

⇒ (x + 2) (x - 1) = 0

⇒ x + 2 = 0 or x - 1 = 0

⇒ x = - 2 or x = 1

Hence, - 2 and 1 are the roots of the given equation.



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