\(324\cdot36-254\cdot72+18\cdot368\)
\(=18\cdot\left(324\cdot2-254\cdot3+368\right)\)
\(=18\cdot\left(648-1016+368\right)\)
\(=18\cdot\left(1016-1016\right)\)
\(=18\cdot0\)
\(=0\)
\(7364-\left(8475-4555\right)-364+445+475\)
\(=7364-8475+4555-364+445+475\)
\(=\left(7364-364\right)-\left(8475-475\right)+\left(4555+445\right)\)
\(=7000-8000+5000\)
\(=4000\)
\(21\cdot32\cdot43-21\cdot32\cdot40-21\cdot32\cdot3\)
\(=21\cdot32\cdot\left(43-40-3\right)\)
\(=21\cdot32\cdot0\)
\(=21\cdot0\)
\(=0\)