Question

Уравнение 23+56-c=70

Answer 1

$\boldsymbol{23+56-c = 70} \\ \\ 79-c = 70\\ \\ -c = 70-79\\\\ -c = -9\\\\ \boldsymbol{c = 9} \\\\ \\ \\ \boxed{ \boldsymbol{OTBET:9} }$

Answer 2

23+56-с=70
23+56=79
с=79-70
с=9
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23+56-9=70
70=70

Удачи))