tìm x thuộc N, x khác 0

1/3+1/6+......+1/45+2/x(x+1)=4027/5040+x/2

1/3 + 1/6 + ......... + 1/45 + 2_{^{x + (x+1) = 4027/5040 = 2}}/x (x khác 0)

Tìm x thuộc N và x ≠ 0, biết \(\frac{1}{3}\)+ \(\frac{1}{6}\)+.............+ \(\frac{1}{45}\)+\(\frac{2}{x\left(x+1\right)}\)= \(\frac{4027}{5040}\)+ \(\frac{2}{x}\)

tìm x

a) \(\dfrac{1}{3}\)+\(\dfrac{1}{6}\)+...+\(\dfrac{1}{45}\)+\(\dfrac{2}{x+\left(x+1\right)}\)=\(\dfrac{4027}{5040}\)+\(\dfrac{2}{x}\)

tìm x, biết : 

a) 1/( x+1 ).( x+2 ) + 1/( x+2 ).( x+3 ) + 1/( x+3 ).( x+4 ) + ... + 1/( x+1999).( x+2000) = 1/x+200 = 1/5 

b) 2/( x+1 ).( x+3 ) + 3/( x+3 ) .( x+6 ) + 4/( x+6 ).( x+10 ) + ... + 10/( x+45 ).( x+55 ) + 1/ x+55 = 1/6 

Tìm x:

a: 1/45+1/55+1/66+.....+2/x*(x+1)=1/9

b:1+1/3+1/6+1/10+.....+1/x*(x+1):2=3984/1993

Bài 2:Tìm x,biết:

1, 4/5-x=1/3

2, 2/3+5/3x=5/7

3, -12/13x+5=5 1/13

4, x:(-2 1/4)+1,5=-3/4

5,GTTĐ của x -3/4 - 1/4=0

6, 6-GTTĐ của 1/2-x = 2/3

7, (x-1)²=4/9

5/6 + 1/2 : 3/4
5/6 - 1/2 x 3/4
1/2 x 1/3 : 1/4
1/2 : 1/3 x 1/4
1/2 : 1/3 : 1/4