Предмет: Математика, автор: arkanovadarina

2x в квадрате+7x-4<0

kusnetsovoksa: и?

Ответы

Автор ответа: romaroma2101

2х²+7х-4=0
D=49+32=81
x=-7+9/2=1
x=-7-9/2=-8
--+---8-----_----1----+----⇒ (типо числовая прямая)
х=2 (2-1)(2=8)= "+"
Следовательно х∈(-8;1)

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