20-20+12-2+2+3-4+2-1-1-1-1-1-1+10000000-2-3-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9

2 câu trả lời

Đáp án:

 

Giải thích các bước giải:

20-20+12-2+2+3-4+2-1-1-1-1-1-1+10000000-2-3-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9

20 - 20 hết, -2 +2 hết, +3 -3 hết

= 0+12-4+2-1-1-1-1-1-1+10000000-2-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9

=12-4+2-1-1-1-1-1-1+10000000-2-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9

+2 - 1 -1 hết

=12-4-1-1-1-1+10000000-2-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9

=12+10000000-2-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9-4-1-1-1-1

= 10000012 - ( 2+4+5+6+7+8+9+1+2+3+4+5+6+7+8+9+4+1+1+1+1)

= 10000012 - 94

= 9999908

 

 

Đá án:

20-20+12-2+2+3-4+2-1-1-1-1-1-1+10000000-2-3-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9

20 - 20-2+2+3 -3 

= 0+12-4+2-1-1-1-1-1-1+10000000-2-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9

=12-4+2-1-1-1-1-1-1+10000000-2-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9+2-1-1

=12-4-1-1-1-1+10000000-2-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9

=12+10000000-2-4-5-6-7-8-9-1-2-3-4-5-6-7-8-9-4-1-1-1-1

=10000012-[2+4+5+6+7+8+9+1+2+3+4+5+6+7+8+9+4+1+1+1+1]

= 10000012 - 94

= 9999908

Chúc bạn học tốt! 

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