\(B=\frac{2^{12}.3^5-4^6.9^2}{\left(2^2.6\right)^6+8^4.3^5}-\frac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
\(C=\frac{1^2}{1.2}.\frac{2^2}{2.3}.\frac{3^2}{3.4}.\frac{4^2}{4.5}\)
\(D=\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+...+\frac{2}{97.99}\)
\(\frac{3}{1.2}+\frac{3}{2.3}+...+\frac{3}{x\left(x+1\right)}=\frac{11}{4}\)
tính A=\(\frac{2^2}{1.3}+\frac{3^2}{2.4}+\frac{4^2}{3.5}+...+\frac{2016^2}{2015.2017}\)
Tìm người có số IQ cao nha ( là người giỏi, nhanh, đúng )
CMR: \(\frac{1}{1.3}+\frac{1}{2.4}+\frac{1}{3.5}+\frac{1}{4.6}+...+\frac{1}{2013.2015}+\frac{1}{2014.2016}\) \(< \frac{3}{4}\)
1.chứng minh rằng : \(\frac{1}{2}!+\frac{2}{3}!+\frac{3}{4}!+...+\frac{99}{100}!< 1\)
2. Chứng minh rằng :\(\frac{1.2-1}{2}+\frac{2.3-1}{3}+\frac{3.4-1}{4}+...+\frac{99.100-1}{100}< 2\)
Tìm x:
a, \(\left|3x-4\right|\le3\)
b, \(\left(\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{99.100}\right)-2x=\frac{1}{2}\)
1) Cho \(\frac{7x+5y}{3x-7y}\)=\(\frac{7z+5t}{3z-7t}\) Chứng minh \(\frac{x}{y}\)=\(\frac{z}{t}\)
2) Tìm x
51x+26y=2000
|x+1.1|+|x+1.2|+|x+1.3|+|x+1.4|=5x
3)Tính
\(\left(\frac{3}{4}-81\right)\)\(\left(\frac{3^2}{5}-81\right)\)\(\left(\frac{3^3}{6}-81\right)\)......\(\left(\frac{3^{2000}}{2003}-81\right)\)
Chưng minh rằng :
\(\frac{1.2-1}{2\text{!}}+\frac{2.3-1}{3\text{!}}+\frac{3.\text{4}-1}{\text{4}\text{!}}+...+\frac{99.100-1}{100\text{!}}< 2\)
\(\frac{1}{3}x.x=\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{99.101}\)
TÌM x