( 189 x 2 x 64 x 2 -189 x 1 x 64 x 1 ) : ( 15 + ...+ 48)
= ( 189( 2 - 1 )64(2-1):( (15+48)+(16+47) +...)
= ( 189x64):1008
=12096:1008
=12
Làm sai thì bổ sung cho mik nha mấy bạn
\((378.132-189.64):\left(12+15+18+...+45+48\right)\)
\(=\left(189.2.132-189.64\right):390\)
\(=(189.264-189.64):390\)
\(=\left(189.\left(264-64\right)\right):390\)
\(=\left(189.200\right):390\)
\(=37800:390=\frac{1260}{13}\)