Question

(3x/7+1):(-4)= -1/28

Answer 1

3x/7+1=-1/28.-4

3x/7+1=1/7

3x/7=1/7-1

3x/7=-6/7

⇒3x=-6

x=-2

Answer 2

Ta có: \(\left(\dfrac{3x}{7}+1\right):\left(-4\right)=\dfrac{-1}{28}\)

\(\Leftrightarrow\dfrac{3x}{7}+1=\dfrac{-1}{28}\cdot\left(-4\right)=\dfrac{1}{7}\)

\(\Leftrightarrow\dfrac{3x}{7}=\dfrac{1}{7}-1=\dfrac{-6}{7}\)

\(\Leftrightarrow3x=-6\)

hay x=-2

Vậy: x=-2