Bài 1 : Tính nhanh 12,5 × ( 100 × 49 ) – ( 3,2 + 1,3 ) × ( 24 × 26 ) – ( 6,2 – 1,7 ) Bài 2 : Tìm x 288,5 – 36,7 – 18,5 × x – 2,5 × x = 245,92

1.

12,5×(100×49)−(3,2+1,3)×(24×26)−(6,2−1,7) 12,5×(100×49)-(3,2+1,3)×(24×26)-(6,2-1,7)

=12,5×4900−4,5×624−4,5=12,5×4900-4,5×624-4,5

=12,5×(4900− 624)×4,5=12,5×(4900- 624)×4,5

=12,5×4276×4,5=12,5×4276×4,5

=240525=240525

 2.288,5−36,7−18,5×x−2,5×x=254,92288,5-36,7-18,5×x-2,5×x=254,92

=15,7×x=33,58=15,7×x=33,58

=527,206=527,206.

Học ~ tốt!!