Question

por favor me ajudem resolva as inequações!!!​

Answer 1

Resposta:

d)

$\sf 6(x - 5) - 2(4x + 2) > 100 \\6x - 30 - 8x - 4 > 100\\6x - 8x > 100 + 30 + 4\\- 2x > 134 \\2x<- 134\\\\x < \dfrac{-134}{2} \\\\x < - 67\\\\S = \{ x \in R | x < - 67 \}$

e)

$\sf 7x - 9 < 2x+ 16 \\7x -2x < 16 + 9 \\5x < 25\\\\x < \dfrac{25}{5} \\\\x < 5 \\S = \{ x \in R | x< 5 \}$

f)

$\sf 3\leq 5 -2x\\2x \leq 5 - 3\\2x \leq 2\\\\x \leq \dfrac{2}{2} \\\\x \leq 1\\\\\\5 -2x \leq 7 \\-2x \leq 7 - 5\\- 2x \leq 2\\2x \geq - 2\\\\x \geq \dfrac{- 2}{2} \\\\x \geq - 1$

$\sf S = \{ x \in R x \leq 1 \;ou\; x \geq -1\}$

Explicação passo-a-passo:

Ao multiplicar muda de operador sinal e inverte > o sinal.