Question

59)Resolva as seguintes inequações do 2°grau em IR:
a)3x - 10x +7< 0
b)-4x +9> 0​

Answer 1

Explicação passo-a-passo:

A)

$\sf 3x - 10x + 7 < 0$

$\sf - 7x + 7 < 0$

$\sf - 7x < - 7$

$\sf \underline{- 7x < - 7 * (-1)}$

$\sf 7x > 7$

$\sf x > \dfrac{7}{7}$

$\sf x > 1$

$\sf S = \left\{x \in \mathbb{R} /~x > 1\right\}$

B)

$\sf - 4x + 9 > 0$

$\sf - 4x > - 9$

$\sf \underline{- 4x > - 9 * (-1)}$

$\sf 4x < 9$

$\sf x < \dfrac{9}{4}$

$\sf S = \bigg\{x \in \mathbb{R} /~x < \dfrac{9}{4}\bigg\}$