a) -1+[tex] \frac{-5}{12} [/tex] = -1-[tex] \frac{5}{12} [/tex] aduci la numitor comun, adică 12 și ai: [tex] \frac{-12-5}{12} [/tex] = [tex] -\frac{17}{12} [/tex]
b) [tex]1+ \frac{-7}{8} [/tex] = [tex]1- \frac{7}{8} = \frac{8-7}{8} = \frac{1}{8} [/tex]
c) [tex] \frac{4}{9} + \frac{-5}{6} + \frac{3}{4} + \frac{-7}{18} [/tex] =
[tex] \frac{4}{9} - \frac{5}{6} + \frac{3}{4} - \frac{7}{18} [/tex] =
[tex] \frac{4*4-6*5+9*3-2*7}{36} = \frac{16-30+27-14}{36} = \frac{-1}{36} [/tex]
d) [tex] \frac{-7}{24} + \frac{5}{18} + \frac{11}{12} + \frac{-4}{9} [/tex] =
[tex]- \frac{7}{24} + \frac{5}{18} + \frac{11}{12} - \frac{4}{9} [/tex] =
[tex] \frac{3*(-7)+4*5+6*11-8*4}{72} = \frac{-21+20+66-32}{72} = \frac{33}{72} [/tex]
Sper că ai înțeles! :)
