bài 1 tính nhanh
a) 3\(\frac{1}{417}\). \(\frac{1}{762}\)-\(\frac{1}{139}\).\(4\frac{761}{762}\)-\(\frac{4}{417.762}\)+\(\frac{5}{139}\)
b) \(5\frac{4}{23}\). \(27\frac{3}{27}\)+ \(4\frac{8}{27}\).\(-5\frac{4}{23}\)
c) \(3\frac{10}{99}\). \(6\frac{1}{4}\)+ \(3\frac{2}{5}\).\(3\frac{3}{4}\)
bài 2 tính tổng
S= 1+2+5+14+...+ \(\frac{3^n+1}{2}\)
Tính tổng: M= 1252/417 . 1/762 - 1/139 . 3809/762 - 2/417 . 2/762 + 5/139
Tính nhanh:
M= 1252/417 . 1/762 - 1/139 . 3809/762 - 2/417 . 2/762 + 5/139
Các bạn giải chi tiết giùm tui nhé!
tính C= \(9.\left(\frac{13-\frac{13}{7}-\frac{13}{289}}{4-\frac{4}{7}-\frac{4}{289}}:\frac{39+\frac{39}{5}+\frac{39}{139}+\frac{39}{31}}{16+\frac{16}{5}+\frac{16}{139}+\frac{16}{31}}\right).\frac{158158}{164164}\)
tính hộ ợ
1. A = \(\frac{154+919+146+781}{823-217+533-139}\)
2. Tỳm x piết : \(\left(\frac{1}{3\cdot5}+\frac{1}{5\cdot7}+\frac{1}{7\cdot9}+...+\frac{1}{19\cdot21}\right)\). x = \(\frac{9}{7}\)
1, Tính \(\frac{1}{2}-\left(\frac{1}{3}+\frac{2}{3}\right)+\left(\frac{1}{4}+\frac{2}{4}+\frac{3}{4}\right)-\left(\frac{1}{5}+\frac{2}{5}+\frac{3}{5}+\frac{4}{5}\right)+...+\left(\frac{1}{100}+\frac{2}{100}+\frac{3}{100}+...+\frac{99}{100}\right)\)2,Tính \(\left(1-\frac{1}{2^2}\right)x\left(1-\frac{1}{3^2}\right)x\left(1-\frac{1}{4^2}\right)x...x\left(1-\frac{1}{n^2}\right)\)
\(\left(-1\frac{1}{6}\right)\left(\frac{1-\frac{3}{5}+\frac{3}{11}-\frac{3}{13}}{\frac{1}{3}-\frac{1}{5}+\frac{1}{11}-\frac{1}{13}}\right):\left(\frac{4-\frac{4}{17}+\frac{4}{19}-\frac{4}{2013}}{5-\frac{5}{17}+\frac{5}{19}-\frac{5}{2013}}\right)\)
tính
Tính
\(B=-1\frac{1}{5}\)\(.\frac{4.\left(3+\frac{1}{3}-\frac{3}{7}-\frac{3}{53}\right)}{3+\frac{1}{3}-\frac{3}{37}-\frac{3}{53}}:\frac{4+\frac{4}{17}+\frac{4}{19}+\frac{4}{2003}}{5+\frac{5}{17}+\frac{5}{19}+\frac{5}{2003}}\)
thực hiện phép tính bằng cách hợp lý
\(-1\frac{1}{5}.\frac{4.\left(3+\frac{1}{3}-\frac{3}{7}-\frac{3}{53}\right)}{3+\frac{1}{3}-\frac{3}{7}-\frac{3}{53}}.\frac{4+\frac{4}{7}+\frac{4}{9}+\frac{4}{2003}}{5+\frac{5}{17}+\frac{5}{19}+\frac{5}{2003}}\)