Question

giải bất pt

3x+4 /7 ≤ 5x-19 /14

Answer 1

\(\dfrac{3x+4}{7}\le\dfrac{5x-19}{14}\)

\(\Leftrightarrow\dfrac{2\left(3x+4\right)}{14}\le\dfrac{5x-19}{14}\)

\(\Leftrightarrow2\left(3x+4\right)\le5x-19\)

\(\Leftrightarrow6x+8\le5x-19\)

\(\Leftrightarrow x\le-27\)

Vậy \(S=\left\{x|x\le-27\right\}\)

Answer 2

\(\dfrac{3x+4}{7}\le\dfrac{5x-19}{14}\)

\(\Leftrightarrow\dfrac{6x+8}{14}\le\dfrac{5x-19}{14}\)

\(\Leftrightarrow6x+8\le5x-19\)

\(\Leftrightarrow6x-5x\le-19-8\)

\(\Leftrightarrow x\le-27\)

 

 

 

Answer 3

⇔2(3x+4)14≤5x−1914⇔2(3x+4)14≤5x−1914

$\iff 2\left(3x+4\right)\le 5x-19$

$\iff 6x+8\le 5x-19$

$\iff x\le -27$

Vậy S={x|x≤−27}