[tex]-4*(2,3*(-\frac{7}{12} )-4)-(3-2,6*(-\frac{7}{12} ))+3*(0,6*(-\frac{7}{12} )-4)=3,8\\2,3*(-\frac{7}{12} )=-\frac{23*7}{10*12} =-\frac{161}{120} \\-\frac{161}{120}-4=-\frac{161}{120}-\frac{480}{120} =-\frac{641}{120} \\-4*(-\frac{641}{120} )=\frac{641}{30} \\2,6*(-\frac{7}{12})=-\frac{13*7}{5*12} =-\frac{91}{60} \\3-(-\frac{91}{60} )=\frac{180}{60} +\frac{91}{60}=\frac{271}{60}[/tex]

[tex]0,6*(-\frac{7}{12} )=-\frac{3*7}{5*12} =-\frac{7}{20} \\-\frac{7}{20}-4=-\frac{7}{20}-\frac{80}{20} =-\frac{87}{20} \\\frac{641}{30} -\frac{271}{60} -(-\frac{87}{20})=\frac{641}{30} -\frac{271}{60} +\frac{87}{20}=\frac{1282-271-783}{60}=\frac{228}{60} =\frac{19}{5} =3\frac{4}{5} =3,8[/tex]