Question

ma ajuta cineva sa rezolv ecuația asta , va rog ​

Answer 1

Răspuns: $x\:\in \:\bigg[-\dfrac{3}{5} ;1\bigg]$

Explicație pas cu pas:

$2\leq 7-5x\leq 10\:\:\:\:\:\:\:\:\:\bigg|-7$

$2-7\leq 7-5x-7\leq 10-7$

$-5\leq -5x\leq 3\:\:\:\:\:\:\:\:\bigg|:(-5)$

$1\geq x\geq -\dfrac{3}{5} \Rightarrow\boxed{\:x\:\in \:\bigg[-\dfrac{3}{5} ;1\bigg]\:}$

Answer 2

$\it 2\leq7-5x\leq10 \Rightarrow \begin{cases} \it 2\leq7-5x \Rightarrow 5x\leq5|_{:5} \Rightarrow x\leq1 \\ \\ \it7-5x\leq10 \Rightarrow 7-10\leq5x \Rightarrow 5x\geq-3 \Rightarrow x\geq-\dfrac{3}{5}\end{cases} \Rightarrow\\ \\ \\ \Rightarrow -\dfrac{3}{5}\leq x \leq1 \Rightarrow x\in\Big[-\dfrac{3}{5},\ \ 1\Big]$