5. Efectuaţi calculele
a)
d)
b)
-(-):

- cu - = +
+ cu + = +
- cu + = -
Rezolvare:
[tex]a)\:\frac{1}{5} +(-\frac{1}{5} )=[/tex]
[tex]=\frac{1}{5} -\frac{1}{5}[/tex]
[tex]=\frac{0}{5}[/tex]
[tex]\boxed{=0}[/tex]
[tex]b)\:-\frac{7}{3} -(+\frac{5}{3} )=[/tex]
[tex]=-\frac{7}{3} -\frac{5}{3}[/tex]
[tex]=-\frac{12}{3}[/tex]
[tex]\boxed{=-4}[/tex]
[tex]c)\:\frac{11}{4} -(-\frac{1}{4} )=[/tex]
[tex]=\frac{11}{4} +\frac{1}{4}[/tex]
[tex]=\frac{12}{4}[/tex]
[tex]\boxed{=3}[/tex]
[tex]d)\:+\frac{1}{3} -(+\frac{4}{3} )=[/tex]
[tex]=\frac{1}{3} -\frac{4}{3}[/tex]
[tex]=-\frac{3}{3}[/tex]
[tex]\boxed{=-1}[/tex]
[tex]e)\:-\frac{2}{5} -(-\frac{7}{5} )=[/tex]
[tex]=-\frac{2}{5} +\frac{7}{5}[/tex]
[tex]=\frac{5}{5}[/tex]
[tex]\boxed{=1}[/tex]
[tex]f)\:\frac{4}{3} +(-\frac{1}{3} )=[/tex]
[tex]=\frac{4}{3} -\frac{1}{3}[/tex]
[tex]=\frac{3}{3}[/tex]
[tex]\boxed{=1}[/tex]
Succes!