\(141\cdot25+216109\cdot3\)
\(=3\cdot47\cdot25+216109\cdot3\)
\(=3\left(47\cdot25+216109\right)\)
\(=3\cdot217284=651852\)
\(523790-305\cdot26\cdot3\)
\(=2\cdot5\cdot52379-2\cdot5\cdot13\cdot61\cdot3\)
\(=10\left(52379-13\cdot61\cdot3\right)\)
\(=10\cdot50000=500000\)