Tính nhanh : a, (0,125 x 10 – 125\10 : 10 ) x 2001 x 2002 x 2003 b, 28 + 62 x a x ( a x 1 – a : 1 ) + 28 x 8 + 28

* Bạn tham khảo nha >v< *

$a, ( 0,125 × 10 – \dfrac{125}{10} ÷ 10 ) × 2001 × 2002 × 2003$

$= ( 1,25 – 12,5 ÷ 10 ) × 2001 × 2002 × 2003$

$= ( 1,25 – 1,25 ) × 2001 × 2002 × 2003$

$= 0 × 2001 × 2002 × 2003$

$= 0$

$b, 28 + 62 × a × ( a × 1 – a ÷ 1 ) + 28 × 8 + 28$

$= 28 × ( 1 + 8 + 1 ) + 62 × a × ( a – a )$

$= 28 × 10 + 62 × a × 0$

$= 280 + 0$ 

$= 280$