\(\left(x-3\right).\left(y-2\right)=7\)
\(\Rightarrow x-3;y-2\inƯ\left(7\right)=\left\{-7;-1;1;7\right\}\)
Ta có bảng sau:
| x-3 | -7 | -1 | 1 | 7 |
|---|---|---|---|---|
| y-2 | -1 | -7 | 7 | 1 |
| x | -4 | 2 | 4 | 10 |
| y | 1 | -5 | 7 | 3 |
Vậy (x;y) là :(-4;1),(2;5),(4;7),(10;3)
làm tương tự
\(\left(1-\frac{1}{4}\right)\left(1-\frac{1}{9}\right)\left(1-\frac{1}{16}\right)\cdot....\cdot\left(1-\frac{1}{256}\right)\cdot x=\frac{108}{7}\)
\(\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot.....\cdot\left(1-\frac{1}{7}\right)=?\)
\(\left(1+\frac{1}{2}\right)\cdot\left(1+\frac{1}{3}\right)\cdot\left(1+\frac{1}{4}\right)\cdot....\cdot\left(1+\frac{1}{98}\right)\cdot\left(1+\frac{1}{99}\right)=\)?
\(a,\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot......\left(1-\frac{1}{18}\right)\cdot\left(1-\frac{1}{19}\right)\cdot\left(1-\frac{1}{20}\right)\)
Tính giá trị biểu thức :
\(\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot....\cdot\left(1-\frac{1}{99}\right)\cdot\left(1-\frac{1}{100}\right)\)
\(\left(1+\frac{1}{2}\right)\cdot\left(1+\frac{1}{3}\right)\cdot\left(1+\frac{1}{4}\right)\cdot...\cdot\left(1+\frac{1}{10}\right)\) = ?
Bài 1:
\(a,\left(x-\frac{1}{2}\right)\cdot\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+......+\frac{1}{90}\right)=\frac{1}{3}\)
\(b,\frac{1}{1\cdot6}+\frac{1}{6\cdot11}+.....+\frac{1}{96\cdot101}=\frac{1}{10\cdot x}\)
\(c,460+85\cdot4=\frac{x+175}{5}+30\)
\(d,\left(x-5\right)\cdot\left(10-9\frac{40}{41}\right):\left(1-\frac{81}{82}\right):\left(1-\frac{204}{205}\right)=2050\)
Tính nhanh:
\(\frac{9,1+10,2+...+17,9+19}{\left(1-\frac{2}{42}\right)\cdot\left(1-\frac{2}{56}\right)\cdot...\cdot\left(1-\frac{2}{2550}\right)\cdot\left(1-\frac{2}{2652}\right)}\cdot\frac{265}{357}\)
Làm nhanh cho mình trước 14h30p 30/7/2016
Ai làm được cho 5 lần tick
\(\)tính giá trị biểu thức :\(\left(1+\frac{1}{2}\right)\cdot\left(1+\frac{1}{3}\right)\cdot\left(1+\frac{1}{4}\right)\cdot...........\left(1+_{\frac{1}{2013}}\right)\)
