Question

a/ \(\frac{-15}{12}x+\frac{3}{7}=\frac{6}{5}x-\frac{1}{2}\)

b/\(\frac{12+x}{7}=\frac{x-4}{3}\)

Answer 1

\(\dfrac{3}{7}+\dfrac{1}{2}=\dfrac{-15}{12}x+\dfrac{6}{5}x\)

\(\Leftrightarrow\)\(\dfrac{-15.5+12.6}{60}x=\dfrac{3.2+1.7}{14}\)

\(\Leftrightarrow\)\(\dfrac{-3}{60}x=\dfrac{13}{14}\)

\(\Leftrightarrow\)\(\dfrac{-1}{20}x=\dfrac{13}{14}\)

\(\Leftrightarrow\)x=-\(\dfrac{13}{14}:\dfrac{1}{20}=-\dfrac{13.20}{14}=-\dfrac{130}{7}\)

Answer 2

3(12+x)=7(x-4)

\(\Leftrightarrow\)36+3x=7x-28

\(\Leftrightarrow\)7x-3x=36+28

\(\Leftrightarrow\)4x=64

\(\Leftrightarrow\)x=16