= \(\left(\frac{1}{49}-\frac{1}{3^2}\right)...\left(\frac{1}{49}-\frac{1}{7^2}\right)..\left(\frac{1}{49}-\frac{1}{49^2}\right)=\left(\frac{1}{49}-\frac{1}{3^2}\right)..\left(\frac{1}{49}-\frac{1}{49}\right)...\left(\frac{1}{49}-\frac{1}{49^2}\right)\)
= \(\left(\frac{1}{49}-\frac{1}{3^2}\right)....0...\left(\frac{1}{49}-\frac{1}{49^2}\right)=0\)
Tính
\(\left(\frac{1}{49}-\frac{1}{3^2}\right)\left(\frac{1}{49}-\frac{1}{4^2}\right)...\left(\frac{1}{49}-\frac{1}{49^2}\right)\)
\(\left(\frac{1}{49}.\frac{1}{3^2}\right).\left(\frac{1}{49}.\frac{1}{4^2}\right)...\left(\frac{1}{49}-\frac{1}{49^2}\right)\)
AI NHANH MK T
Tìm x, biết :
a, \(60\%x+0,4x+x:3=2\)
b, \(\left|2x-5\right|-7=\left(\frac{1}{49}-\frac{1}{3^2}\right)\left(\frac{1}{49}-\frac{1}{4^2}\right)...\left(\frac{1}{49}-\frac{1}{2015^2}\right)\)
c, \(\frac{x+1}{1}+\frac{2x+3}{3}+\frac{3x+5}{5}+...+\frac{20x+39}{39}=22+\frac{4}{3}+\frac{6}{5}+...+\frac{40}{39}\)
Tìm \(x\) biết:
a)\(\left|2x-5\right|-7=\left(\frac{1}{49}-\frac{1}{3^2}\right)\left(\frac{1}{49}-\frac{1}{4^2}\right).....\left(\frac{1}{49}-\frac{1}{2015^2}\right)\)
b)\(\frac{x+1}{1}+\frac{2x+3}{3}+\frac{3x+5}{5}+...+\frac{20x+39}{39}=22+\frac{4}{3}+\frac{6}{5}+...+\frac{40}{39}\)
Tính:
\(\left(\frac{\left(6-4\frac{1}{2}\right):0,03}{\left(3\frac{1}{20}-2,65\right).4+\frac{2}{5}}-\frac{\left(0,3-\frac{3}{20}\right).1\frac{1}{2}}{\left(1,88+2\frac{3}{25}\right).\frac{1}{80}}\right):\frac{49}{60}\)
Tính hợp lý ( nếu có thể):
\(\left(1+\frac{1}{2}\right)\left(1+\frac{1}{3}\right)\left(1+\frac{1}{4}\right)...\left(1+\frac{1}{49}\right)\)
Bài 1: Thực hiện phép tính:
d / \(\left(\frac{1}{2}+1\right).\left(\frac{1}{3}+1\right).\left(\frac{1}{4}+1\right)....\left(\frac{1}{49}+1\right)\)
Bài 1: Thực hiện phép tính:
d / \(\left(\frac{1}{2}+1\right).\left(\frac{1}{3}+1\right).\left(\frac{1}{4}+1\right)....\left(\frac{1}{49}+1\right)\)
\(182.\left(\frac{1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}}{2+\frac{2}{3}+\frac{2}{9}+\frac{2}{27}}:\frac{4-\frac{4}{7}+\frac{4}{49}-\frac{4}{343}}{1-\frac{1}{7}+\frac{1}{49}-\frac{1}{343}}\right):\frac{919191}{808080}\)
