Question

calculati: 7,(15)+2,(18)-5,(23)+11,(20)

Answer 1

[tex]7,(15)+2,(18)-5,(23)+11,(20)=\\ 9,(33)-5,(23)+11,(20)=\\ 4,(10)+11,(20)=\\ 15,(30)[/tex]

Answer 2

$7,(15)+2,(18)-5,(23)+11,(20)= \\ \\ = \frac{715-7}{99} + \frac{218-2}{99}- \frac{523-5}{99}+ \frac{1120-11}{99}= \\ \\ = \frac{715-7+218-2-523+5+1120-11}{99}= \\ \\ = \frac{1515}{99}= \\ \\ = \boxed{ \frac{505}{33} }$