\(\left(\dfrac{3x}{7+1}\right):\left(-4\right)=\dfrac{-1}{28}\)
\(\dfrac{3x}{7+1}=-\dfrac{1}{28}\cdot\left(-4\right)\)
\(\dfrac{3x}{7+1}=\dfrac{1}{7}\)
\(\dfrac{3x}{8}=\dfrac{1}{7}\)
\(3x=\dfrac{\left(1\cdot8\right)}{7}\)
\(3x=\dfrac{8}{7}\)
\(x=\dfrac{8}{7}:3\)
\(x=\dfrac{8}{7}\cdot\dfrac{1}{3}\)
\(x=\dfrac{8}{21}\)
câu hỏi đúng đây ạ
((3x)/(7)+1)-:(-4)=-(1)/(28)
\(\left(\dfrac{3x}{7}+1\right):\left(-4\right)=-\dfrac{1}{28}\)
\(\dfrac{3x}{7}+1=\left(-\dfrac{1}{28}\right)\cdot\left(-4\right)\)
\(\dfrac{3x}{7}+1=\dfrac{1}{7}\)
\(\dfrac{3x}{7}=\dfrac{1}{7}-1\)
\(\dfrac{3x}{7}=-\dfrac{6}{7}\)
\(3x=\dfrac{\left(-6\cdot7\right)}{7}\)
\(3x=-6\)
\(x=\left(-6\right):3\)
\(x=-2\)
