Question

${2x}^{2} + 9x - 5 = 0$
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Answer 1

Ответ:

-5  ; 0.5

Объяснение:

$2x^{2} +9x-5=0\\2x^2+10x-x-5=0\\2x(x+5)-(x+5)=0\\(2x-1)(x+5)=0\\2x-1=0\\2x=1\\x=0.5\\x+5=0\\x=-5$

Answer 2

D = b^2 - 4ac

D = 81 - 4(2 * (-5)) = 81 - 4 * (-10) = 81 + 40 = 121 = 11^2

x1 = (-9 + 11) / 2 * 2 = 2/4 = 0,5

x2 = (-9 - 11) / 2 * 2 =- -20/4 = -5