1000 + 2 × ( 25 + 52 ) =
= 1000 + 2 × 77
= 100 + 154
= 254
3000 - ( 2100 - 20 × 100 ) : 10 =
= 3000 - ( 2100 - 200 ) : 10 =
= 3000 - 1900 : 10 =
= 3000 - 190 =
= 1100
6 × ( 30 × 50 - 24 × 24 ) - 800 =
= 6 × ( 1500 - 24 × 24 ) - 800 =
= 6 × ( 1500 - 576 ) - 800 =
= 6 × 924 - 800 =
= 5544 - 800 =
= 4744