Răspuns:
7.
a)3/8
b)-4/3
8.
a)25/6
b)19/36
Explicație pas cu pas:
[tex]7. a)\frac{1}{2}+1\frac{1}{4}+(-\frac{3}{8})=\\\frac{1}{2}+\frac{1}{4}-\frac{3}{8}=\\\frac{2}{4}+\frac{1}{4}-\frac{3}{8} =\\\frac{2+1}{4}-\frac{3}{8}=\\\frac{3}{4}-\frac{3}{8}=\\\frac{6}{8}-\frac{3}{8}=\\\frac{6-3}{8}=\\\frac{3}{8}\\[/tex]
[tex]d) (-2\frac{1}{4})+(-\frac{2}{3})+\frac{5}{12}=\\\frac{-2}{4}-\frac{2}{3}+\frac{5}{12}=\\-\frac{1}{2}-\frac{2}{3}+\frac{5}{12}=\\-\frac{3-4}{6}+\frac{5}{12}=\\-\frac{14}{12}+\frac{5}{12}=\\\frac{-14+5}{12}=\\\frac{-9}{12}=\\-\frac{3}{4}[/tex]
[tex]8. a)3\frac{1}{2} +\frac{2}{3} =\\\frac{6+1}{2}+\frac{2}{3} =\\\frac{7}{2}+\frac{2}{3}=\\\frac{21}{6}+\frac{4}{6}=\\\frac{21+4}{6}=\\\frac{25}{6}[/tex]
[tex]d) (-\frac{3}{4})+1\frac{5}{18}=\\-\frac{3}{4}+\frac{18+5}{18}=\\-\frac{3}{4}+\frac{23}{18} =\\-\frac{27}{36}+\frac{46}{36}=\\\frac{-27+46}{36}=\\\frac{19}{36}[/tex]
