1\5*8+1\8*11+....+1\x*(x+3)=101/1540
1/5-1/8+1/8-1/11+....+1/x-1/(x+3)=101/1540
1/5-1/(x+3)=101/1540
1/(x+3)=1/5-101/1540
1/(x+3)=207/1540
x+3=1540/207
x=1540/207-3
x=919/207
Tính tổng 1000 số hạng trong dãy số sau
\(1\frac{1}{3};1\frac{1}{8};1\frac{1}{15};...\)
Tìm x :
\(\frac{1}{5\cdot8}+\frac{1}{8\cdot11}+\frac{1}{11\cdot14}+...+\frac{1}{x\left(x+3\right)}=\frac{101}{1540}\)
\(\frac{1}{5\cdot8}\)+ \(\frac{1}{8\cdot11}\)+ \(\frac{1}{11\cdot14}\)+ . . . + \(\frac{1}{3\cdot\left(x+3\right)}\)=\(\frac{101}{1540}\)
tim x biet :
a )\(\frac{1}{5.8}+\frac{1}{8.11}+...+\frac{1}{x\left(x+3\right)}=\frac{101}{1540}\)
b) \(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{1}{x\left(x+1\right).2}=1\frac{1991}{1993}\)
Tim x
\(\frac{x+2015}{5}+\frac{x+2016}{4}=\frac{x+2017}{3}+\frac{x+2018}{2}\)
2/ tim x
\(\frac{x+2015}{5}+\frac{x+2016}{6}=\frac{x+2017}{7} +\frac{x+2018}{8}\)
3/ tim x
\(\frac{1}{3}+\frac{1}{6}+\frac{99}{101}+\frac{1}{15}+... +\frac{1}{x\left(2x+1\right)}=\frac{1}{10}\)
1)tìm x
a)(1/3-5/6.x)^3+21/54=5/6
b)1/12-1/3(1/2.x-1)^4=1/16
c)(3/5)^x-1+5.(3/5)^x-1=54/25
d)(2/3)^x+(2/3)^x+2=101/243
2) so sánh
a)1/27^11 và 1/81^8
b)1/3^99 và 1/11^21
1)tìm x
a)(1/3-5/6.x)^3+21/54=5/6
b)1/12-1/3(1/2.x-1)^4=1/16
c)(3/5)^x-1+5.(3/5)^x-1=54/25
d)(2/3)^x+(2/3)^x+2=101/243
2) so sánh
a)1/27^11 và 1/81^8
b)1/3^99 và 1/11^21
tìm x biết
a 1/5.8+1/8.11+1/11.14+...1/x(x+3)=101/1540
b 1+1/3+1/6+1/10+...1/x(x+1)=\(1\frac{1991}{1993}\)
tìm x biết
1) x=-1/2 + 3/4 2) x - 1/5 = 2/11 3) x - 5/6 = 16/42 + -8/56
4) x/5 = 5/6 + -19/30 5) |x| - 1/4 = 6/18 6)x = -1/2 +3/4
7) x/15 = 3/5 + -2/3 8)11/8 + 13/6 = 85/x 9) x - 7/8 = 13/12
10) x - -6/15 = 4/27 11) -\(\dfrac{-6}{12}\)+ x = 9/48 12) x - 4/6 = 5/25 + -7/15
tim x biết 13/19-3/8 < x -1/5 < 11/15+2/3
