a) \(64\cdot25+35\cdot25+25=25\cdot\left(64+35+1\right)=2500\)
b) \(92\cdot42+32\cdot8+5\cdot16\)
\(=8\cdot21\cdot23+16\left(16+5\right)\)
\(=8\cdot21\cdot23+16\cdot21\)
\(=8\cdot21\cdot\left(23+2\right)\)
\(=8\cdot21\cdot25\)
\(=2\cdot21\cdot4\cdot25\)
\(=42\cdot100\)
\(=4200\)
c) \(\left(42\cdot43+43\cdot57+43\right)-360:4\)
\(=\left[43\cdot\left(42+57+1\right)\right]-360:4\)
\(=4300-90\)
\(=4210\)
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