5 + 6 ⋅ 7 − 55 : ( 21 − 4 ⋅ 8 ) − 3 ⋅ [ 7 + 2 ⋅ ( 6 ⋅ 3 − 39 : 3 ) ] − 57 {\displaystyle \ 5+6\cdot 7-55:(21-4\cdot 8)-3\cdot [7+2\cdot (6\cdot 3-39:3)]-57\ }
5 + 6 ⋅ 7 − 55 : ( 21 − 4 ⋅ 8 ⏟ ( − 11 ) ) 21 − 32 = − 11 − 3 ⋅ [ 7 + 2 ⋅ ( 6 ⋅ 3 18 − 39 : 3 ) 13 ⏟ 5 18 − 13 = 5 ⏟ 2 ⋅ 5 = 10 ] ⏟ 7 + 10 ⏟ 17 − 57 = 5 + 6 ⋅ 7 42 − 55 : ( − 11 ) − 5 + 3 ⋅ 17 51 − 57 5 + 42 + 5 − 51 − 57 = − 56 {\displaystyle {\begin{array}{c}5+6\cdot 7-55:{\cancelto {21-32=-11}{(\underbrace {21-4\cdot 8} _{(-11)})}}-3\cdot \underbrace {{\Bigl [}7+{\color {blue}{\underbrace {\color {red}{{\color {blue}2}\cdot {\cancelto {18-13=5}{\underbrace {({\overset {18}{6\cdot 3}}-{\overset {13}{39:3)}}\quad } _{5}}}}} _{2\quad \cdot \quad {\color {red}{5}}\ \ =\ \ 10}{\color {black}{\Bigr ]}}}}} _{\underbrace {7\qquad +\quad {\color {blue}10}} _{17}}-57=\\\\5+{\cancelto {42}{6\cdot 7}}-{\cancelto {-5}{55:(-11)}}+{\cancelto {51}{3\cdot 17}}-57\\\\5+42+5-51-57=-56\end{array}}}
![{\displaystyle \ 5+6\cdot 7-55:(21-4\cdot 8)-3\cdot [7+2\cdot (6\cdot 3-39:3)]-57\ }](https://wikimedia.org/api/rest_v1/media/math/render/svg/b14ded05216ae2dbaadbd87d2306bc2aa672416b)
![{\displaystyle {\begin{array}{c}5+6\cdot 7-55:{\cancelto {21-32=-11}{(\underbrace {21-4\cdot 8} _{(-11)})}}-3\cdot \underbrace {{\Bigl [}7+{\color {blue}{\underbrace {\color {red}{{\color {blue}2}\cdot {\cancelto {18-13=5}{\underbrace {({\overset {18}{6\cdot 3}}-{\overset {13}{39:3)}}\quad } _{5}}}}} _{2\quad \cdot \quad {\color {red}{5}}\ \ =\ \ 10}{\color {black}{\Bigr ]}}}}} _{\underbrace {7\qquad +\quad {\color {blue}10}} _{17}}-57=\\\\5+{\cancelto {42}{6\cdot 7}}-{\cancelto {-5}{55:(-11)}}+{\cancelto {51}{3\cdot 17}}-57\\\\5+42+5-51-57=-56\end{array}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c8412b89765e410f52719902acb83f44dcff55ad)
