Question

solve the quadratic equation 9x^2-3x-20=0 by the method of factorisation.

Answer 1

split 3 by 15 and 12 .......

u will get the answer

Answer 2

Solving quadratic equation by Factorisation Method:

$Given \: quadratic \: equation :\\</p><p>9x^{2} - 3x - 20 = 0$

/* Splitting the middle term,we get */

$9x^{2} - 12x + 15x - 20 = 0$

$\implies 3x( 3x - 4 ) + 5( 3x - 4 ) = 0$

$\implies ( 3x - 4 )( 3x + 5 ) = 0$

$\implies 3x - 4 = 0 \: Or \: 3x + 5 = 0$

$\implies 3x = 4 \: Or \: 3x = - 5$

$\implies x = \frac{4}{3} \: Or \: x = \frac{-5}{3}$

Therefore.,

$\green { x = \frac{4}{3} \: Or \: x = \frac{-5}{3} }$

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