\(K=1+\frac{1}{3}+\frac{1}{9}+...+\frac{1}{243}+\frac{1}{729}\)
\(3K=3+1+\frac{1}{3}+...+\frac{1}{81}+\frac{1}{243}\)
\(3K-K=3-\frac{1}{729}\)
\(2K=\frac{2186}{729}\)
\(K=\frac{1093}{729}\)
Tính nhanh : 1/3 + 1/9 + 1/27 + 1/81 + 1/243 + 1/729
Tính nhanh
1\3+1\9+1\27+1\84+1\243
tính nhanh :
1/3+1/9+1/27+1/81+1/243
Tính nhanh:
1 + 1/3 + 1/9 + 1/27 + 1/81 + 1/243 + 1/729
1+1/3+1/9+1/27+1/81+1/243
tính nhanh
1 + 1/3 + 1/9 + 1/27 ++ 1/81 + 1/243
KHỬ LIÊN TIẾP ( TÍNH NHANH )
Tính nhanh:
1+ 1/3 + 1/9 + 1/27 + 1/81 + 1/243 + 1/729
tính nhanh
a) 1/2+1/4+1/8+1/16+1/32
b) 1/3+1/9+1/27+1/81+1/243+1/729
tính nhanh
1/3+1/9+1/27+1/81=1/243=1/729
