Luam fiecare caz:
a.
[tex]2* (- \frac{2}{7} ) - 7=0 =\ \textgreater \ - \frac{4}{7} -7=0 =\ \textgreater \ \frac{-4-49}{7}=0 =\ \textgreater \ \frac{-53}{7}=0 (F)[/tex]
b.
[tex]7*(- \frac{2}{7} )+3 =5 =\ \textgreater \ -2+3=5 =\ \textgreater \ 1=5 (F)[/tex]
c.
[tex]7*(- \frac{2}{7} )+2 = 0 =\ \textgreater \ -2+2=0 =\ \textgreater \ 0=0 (A)[/tex]
d.
[tex]9*(- \frac{2}{7} )-3 = 2* (- \frac{2}{7} ) =\ \textgreater \ - \frac{39}{7} = - \frac{4}{7} (F)[/tex]
Deci [tex] -\frac{2}{7} [/tex] este solutie pentru C. 7x+2=0
