Question

Factorise : 3x2 – 11x – 20​

Answer 1

⠀☆ GIVEN⠀ POLYNOMIAL  – 3x² - 11x  - 20 :

⠀⠀⠀⠀

$:\implies\sf 3x^2-11x - 20 = 0 \\\\\\\star \sf{By \:Using\:Sum-Product \:Pattern\::}\\\\ \:\implies\sf 3x^2 + 4x - 15x - 20= 0 \\\\\\\star\sf{Finding\:out\:Common\:Terms\::}\\\\\\:\implies\sf x(3x + 4) -5(3x + 4) = 0\\\\\\\star\sf{Now,\:Rewrite\:in\:Factored\:term\::}\\\\\\:\implies\sf (x - 5)\; (3x + 4) = 0\\\\\\:\implies{\underline{\boxed{\frak{\purple{(x-5)(3x+4)}}}}}\;\bigstar$

Therefore,

⠀⠀⠀⠀⠀$\therefore {\underline{ \mathrm { Hence, \:The\:factors\:are\:\bf{(x-5)\:and \:(3x+4)\: }}}}$

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Answer 2

Solution :

= 3x² - 11x - 20

= 3x² - 15x + 4x - 20

= 3x(x - 5) + 4(x - 5)

= (x - 5)(3x + 4)