18 x 123 + 9 x 4567 x 2 + 3 x 5310 x 6
= 18 x ( 123 + 4567 + 5310 )
= 18 x 10000
= 180000
( 2 + 4 + 6 + 8 + ... + 22 ) + 48
= ( 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18 + 20 + 22 ) + 48
= 132 + 48
= 180
k mình nha
( 2 + 4 + 6 + 8 + ....... + 22 ) + 48
= ( 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18 + 20 + 22 ) + 48
= ( ( 2 + 22 ) + ( 4 + 20 ) + ( 4 + 18 ) + ( 8 + 16 ) + ( 10 + 14 ) + 12 ) + 48
= ( 24 + 24 + 24 + 24 + 24 + 12 ) + 48
= 132 + 48
= 180
k mình nha