Răspuns :
[tex]\it\Big (\dfrac{^{2)}5}{\ 9}-\dfrac{^{3)}1}{\ 6}+\dfrac{7}{18}\Big)\cdot\Big(\ ^{7)}1-\dfrac{1}{7}\Big)=\dfrac{10-3+7}{18}\cdot\dfrac{7-1}{7}=\dfrac{14}{18}\cdot\dfrac{6}{7}=\dfrac{2}{3}[/tex]
[tex]\it\Big (\dfrac{^{2)}5}{\ 9}-\dfrac{^{3)}1}{\ 6}+\dfrac{7}{18}\Big)\cdot\Big(\ ^{7)}1-\dfrac{1}{7}\Big)=\dfrac{10-3+7}{18}\cdot\dfrac{7-1}{7}=\dfrac{14}{18}\cdot\dfrac{6}{7}=\dfrac{2}{3}[/tex]