tính nhanh 1.2.3....9 - 1.2.3....8 - 1.2.3......8^2
nhưng bạn ơi mk cần cách tính làm sao cho nhanh
mk vẫn thắc mắc sao 1.2.3.....9- 1.2.3.4.8^2 lại bằng 1.2.3.4.5....9
Tính nhanh: 1.2.3...9-1.2.3...8-1.2.3...7.\(8^2\)
Trình bày lời giải đầy đủ giúp mk nha \(please\)
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
1.2.3. . . 9-1.2.3. . .8-1.2.3. . .7.82
giup minh bai nay nha. Nhanh nhanh cang tot nha.
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...9 - 1.2.3...8 - 1.2.3...7.82
= 1.2.3...9 - 1.2.3...8 - 1.2.3...8.8
= 1.2.3...8(9 - 1 - 8)
= 1.2.3...8.0
= 0
\(1.2.3.....9-1.2.3.....8-1.2.3...8.8\)
Giair nhanh mình tick!
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
Bài 1 Tính nhanh
1.2.3...9-1.2.3...8-1.2.3...7.8.8
1152-(374+1152)+(-65+374)
13-12+11+10-9+8-7-6+5-4+3+2-1
Tính nhanh:
9) 1 . 2 . 3 . ..... 9 - 1.2.3 . ..... 8 - 1.2.3 . .... 8\(^2\)
10) 47 . ( 23 + 50 ) - 23 . ( 47 + 50)
1.2.3...9 - 1.2.3...8 - 1.2.3...7.82
\(1.2.3.....9-1.2.3.....8-1.2.3.....7.8^2\)
\(=1.2.3.....8\left(9-1-8\right)\)
\(=1.2.3.....8\cdot0\)
\(=0\)
1.2.3.....9−1.2.3.....8−1.2.3.....7.821.2.3.....9−1.2.3.....8−1.2.3.....7.82
=1.2.3.....8(9−1−8)=1.2.3.....8(9−1−8)
=1.2.3.....8⋅0=1.2.3.....8⋅0
=0
1.2.3...9-1.2.3...8-1.2.3...7.82
1.2.3...9-1.2.3...8-1.2.3...8^2
Giải thích giùm mình nha
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
\(1.2.3.....9-1.2.3.....8-1.2.3.....8^2\)
\(=1.2.3.....8.\left(9-1\right)-1.2.3.....8.8\)
\(=1.2.3.....8.8-1.2.3.....8.8\)
\(=0\)