810 - 89 - 88
= 88(82 - 8 - 1)
= 88. 55 \(⋮\)55 (đpcm)
Ta có: 810 - 89 - 88 = 88.( 82 - 8 - 1 ) = 88. 55
Vì 55\(⋮\)55 \(\Rightarrow\left(8^8.55\right)⋮55\)
\(\Rightarrow8^{10}-8^9-8^8⋮55\)(đpcm)
\(\text{Ta có : }8^{10}-8^9-8^8\)
\(=8^8.\left(8^2-8-1\right)\)
\(=8^8.\left(64-8-1\right)\)
\(=8^8.55⋮55\)
\(\Rightarrow8^{10}-8^9-8^8⋮55\left(\text{đpcm}\right)\)
\(8^{10}-8^9-8^8\)
\(=8^8.8^2-8^8.8-8^8.1\)
\(=8^8.\left(8^2-8-1\right)\)
\(=8^8.\left(64-8-1\right)\)
\(=8^8.55⋮55\left(đ.p.c.m\right)\)
\(8^{10}-8^9-8^8\)
\(=8^8\left(8^2-8-1\right)\)
\(=8^8\left(64-8-1\right)\)
\(=8^8.55:55\)
\(=8^{10}-8^9-8^8⋮55\)
\(\Rightarrowđpcm\)
\(8^{10}-8^9-8^8\)
\(=8^8\left(8^2-8-1\right)\)
\(=8^8\left(64-8-1\right)\)
\(=8^8\left(56-1\right)\)
\(=8^8.55⋮55\)\(\left(đpcm\right)\)
