Tìm x biết: a) 34x+4=9x+2
b) 3.(1/5.8 + 1/8.11 + 1/11.14 +........+ 1/97.100+x) =319/100
c) (6-x)2014=(6-x)2015
d) 2+4+6+...+2.x=210
e) 1/21+1/28+1/36+...+2/x.(x+1) = 2/9
bài 1 Rút gọn B=(1 -1/3).(1 -1/6).(1 -1/10).(1 -1/15)...(1 -1/190)
Bài 2 Tìm x biết
a) 1/21+ 1/28+ 1/36+..+1/x(x+1)=2/9
b)1/5.8 + 1/8.11+ 1/11.14+..+1/x(x+3)=101/1540
tìm x :
a, 1/5.8+1/8.11+11/11.14+...+1/x.(x+3)=101/1540
b, 1+1/3+1/6+1/10+...+1/x.(x+1):2=1 và 1991/1993
tìm x biết
1/5.8+1/8.11+1/11.14+...+1/x(x+3)=101/15401+1/3+1/6+1/10+...+1/x(x+1):2=1 1991/19931/5.8+1/8.11+....+1/y(y+3)=98/1545 tìm x,y
2x+7/6+13/12+21/20+31/30+43/42+57/56+73/72+91/90=10
1/2013.x+1+1/2+1/6+....+1/2012.2013=2
1+1/3+1/6+1/10+...+1/2012.2013=2
1/21+1/28+1/36+...+2/x(x+1)=2/9
ai nhanh mình tik cho
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):2 = \(1\frac{1991}{1993}\)
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):2 = \(1\frac{1991}{1993}\)
Tìm x,biết rằng:
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):2=1 1991/1993
*1 1991/1993 là hỗn số nha
tìm x; 3.x/2.5 + 3.x/5.8 + 3.x/8.11 + 3.x/11.14= 1/21
làm giúp mình với nha, mình đang cần gấp lắm