`1/2+1/6+1/12+....+1/(x(x+1))=99/100`
`-> 1/(1.2)+1/(2.3)+1/(3.4)+....+1/(x(x+1))=99/100`
`-> 1 - 1/2 + 1/2 -1/3 +1/3-1/4+....+1/x -1/(x+1)=99/100`
`-> 1-1/(x+1)=99/100`
`-> x/(x+1)=99/(99+1)`
`-> x=99`
1 .
a) 1/2 + 1/6 + 1/12 +....+1/x.(x+1) = 99/100
1 .
a) 1/2 + 1/6 + 1/12 +....+1/x.(x+1) = 99/100
1 .
a) 1/2 + 1/6 + 1/12 +....+1/x.(x+1) = 99/100
tìm x thuộc Z
a)1+2+3+.........+x=5050
b)1/2+1/6+........1x2+x=99/100
c)1/6+1/12+.......1/x2-x=59/100
d)x-2017+x-2016+.........+99+100=0
g)x-1+x-2+x-3+.......x-2017=0
Tìm x biết :
1/2 + 1/6 + 1/12 + ... + 1/x = 99/100
Tìm x biết rằng :
1/2 + 1/6 + 1/12 + .... + 1/x = 99/100
Tinh :
1+2+2^2+2^3+...+2^100
Tim x
X : 2 +x:6 +x:12+...+x:9900 = 99
x :(1/2)+x:(1/4)+x:(1/8) +...+ x:(1/512)=511
a ) 1 + 2 + 3 + 4 +.................+ 98 + 99
b ) 2 + 4 + 6 +.............+ 100
c ) 1 x 2 + 2 x 3 + ............+ 99 x 100
Mọi người giúp mik bài nài nhé !
3 x 25 x 8 + 6 x 4 x 37 + 2 x 38 x 12.A = 1 x 2 + 2 x 3 + 3 x 4 + 4 x 5 + 5 x 6 +...+ 99 x 100B = 1 x 3 + 2 x 4 + 3 x 6 + 4 x8...+ 99 x 101 C = 4 + 12 + 24 + 40 + ... + 19404 + 19800
