( 500 x 9 - 250 x 2 x 9 ) x ( 1 + 2 + 3 .... +9 )
\(=9\times\left(500-250\times2\right)\times\left(1+2+...+9\right)\\ =9\times\left(500-500\right)\times\left(1+2+...+9\right)\\ =9\times0\times\left(1+2+...+9\right)=0\)
\(\left(500\cdot9-250\cdot2\cdot9\right)\cdot\left(1+2+3+...+9\right)\)
\(=\left(500\cdot9-500\cdot9\right)\left(1+2+3+...+9\right)\)
\(=0\cdot\left(1+2+3+...+9\right)=0\)
( 500 x 9 - 250 x 2 x 9 ) x ( 1 + 2 + 3 .... +9 )
=(500.9-500.9).(1+2+3...+9)
=0.(1+2+3...+9)
=0