a/ 1.2.3...9-1.2.3...8-1.2.3...7.82
1.2.3...9 - 1.2.3...8 - 1.2.3...7.82
\(1.2.3.....9-1.2.3.....8-1.2.3.....7.8^2\)
\(=1.2.3.....8\left(9-1-8\right)\)
\(=1.2.3.....8\cdot0\)
\(=0\)
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
A= 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
Chúc bạn học tốt
\(A=1.2.3...9-1.2.3...8-1.2.3...8.8\)
\(=1.2.3...8.\left(9-1-8\right)\)
\(=1.2.3...8.0\)
\(=0\)
A = 1.2.3....9 - 1.2.3...8 - 1.2.3.....8.8
Thực hiện phép tính
a, 1.2.3. ... .9-1.2.3. ... .8-1.2.3. ... .8^2
1.2.3.4.....9-1.2.3.4....8-1.2.3...8.8=1.2.3.....8.(9-1)-1.2.3.4....8.8=1.2.3....8.8-1.2.3....8.8=0
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
\(1.2.3.....9-1.2.3.....8-1.2.3.....8^2\)
\(=1.2.3.....8.\left(9-1\right)-1.2.3.....8.8\)
\(=1.2.3.....8.8-1.2.3.....8.8\)
\(=0\)
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
1.2.3....9-1.2.3...8-1.2.3....7.8.8
1.2.3....9-1.2.3....8-1.2.3....7.8.8
= 1.2.2...9-1.2.3....8-1.2.3....7.8^2
= 8! . 9 . 8! .1 - 8! .8
= 8!.( 9-1-8)
= 8! . 0
= 0
tk mik nếu đúng nha ~!
b) 1.2.3...9-1.2.3...8-1.2.3...7.8^ 2
1.2.3...9 - 1.2.3...8 - 1.2.3....7.82
= 1.2.3.4.5.6.7.8.(9 - 1 - 8)
= 1.2.3.4.5.6.7.8.0
= 0