c: \(126\cdot484+252\cdot258\)
\(=126\cdot484+126\cdot2\cdot258\)
\(=126\left(484+2\cdot258\right)\)
\(=126\cdot1000=126000\)
d: \(124\cdot45+124\cdot235-248\cdot40\)
\(=124\cdot45+124\cdot235-124\cdot80\)
\(=124\left(45+235-80\right)\)
\(=124\cdot200=24800\)
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