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mk vẫn thắc mắc sao 1.2.3.....9- 1.2.3.4.8^2 lại bằng 1.2.3.4.5....9
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1.2.3...9 - 1.2.3...8 - 1.2.3...82
= 1.2.3...8.(9 - 1) - 1.2.3...82
= 1.2.3...8.8 - 1.2.3...8.8
= 0
1.2.3...9 - 1.2.3...8 - 1.2.3...82
= 1.2.3...8.(9 - 1) - 1.2.3...82
= 1.2.3...8.8 - 1.2.3...8.8
= 0
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cau b ta co9;(x+x+.....+x)-(1+2+....+100)=4950
100x - 5050 =4950
100x =4950+5050
100x =10000
x=10000 ;100
x=100
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1.2.3...9 - 1.2.3...8 - 1.2.3...7.82
= 1.2.3....8.9 - 1.2.3....8 - 1.2.3...7.8.8
= (1.2.3...8).9 - (1.2.3...8).1 - (1.2.3....7.8).8
= (1.2.3...8). (9 - 1 - 8) = (1.2.3...8) . 0 = 0
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1.2.3....9-1.2.3....8-1.2.3...8.8= 1.2.3....9-(12.3....8+1.2.3...8.8)=1.2.3...9-(1.2.3....8(1+8)=1.2.3....9-1.2.3....9=0
đang ký trang youtube này dùm nha https://www.youtube.com/channel/UCdMJRiuo_35tKETQtnAYOBQ
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1.2.3......9-1.2.3....8-1.2.3.....7.82
= 8!..9-8!..1-8!..8
=8!(9-1-8)
=8!.0
=0
k cho mk nhé
=1.2.3...8.(9-1-8)=0