Предмет: Алгебра, автор: juventus2008nikita

Чому дорівнює сума коренів рівняння 2х^2+5х-12=0

Ответы

Автор ответа: MatemaT123

1

Ответ:

$-2,5$

Объяснение:

$2x^{2}+5x-12=0 \quad |:2$

$x^{2}+2,5x-6=0;$

Воспользуемся теоремой Виета:

$\displaystyle \left \{ {{x_{1}+x_{2}=-2,5} \atop {x_{1} \cdot x_{2}=-6}} \right. ;$

Сумма корней равна –2,5.

Автор ответа: Аноним

0

ответ:

$\displaystyle -4+1,5=-2,5$

$\displaystyle 2x^2+5x-12=0\\2x^2+8x-3x-12=0\\2x(x+4)-3(x+4)=0\\(x+4)(2x-3)=0\\x+4=0,2x-3=0\\\\x_1=-4,x_2=\frac{3}{2}=1,5$

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