\(\dfrac{1}{4}+\dfrac{1}{3}:\left(3x\right)=-5\)
\(\dfrac{1}{3}:\left(3x\right)=-5-\dfrac{1}{4}\)
\(\dfrac{1}{3}:\left(3x\right)=-\dfrac{21}{4}\)
\(3x=\dfrac{1}{3}:\left(-\dfrac{21}{4}\right)\)
\(3x=-\dfrac{4}{63}\)
\(x=-\dfrac{4}{63}:3\)
\(x=-\dfrac{4}{189}\)