Các câu hỏi tương tự
Tìm x (nhanh):
a, 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56 + 1/72 + 1/90 + x = 3/5
b, 2/3.5 + 2/5.7 + ... + 2/13.15 + x = 1/3
c, 1/2 + 1/6 + 1/12 + 1/20 + ... + 1/x( x + 1) = 9/10
Ở cậu b dấu chấm là dấu nhân đấy nhé!!!
Giải ra nhé!!!
20 tháng 8 2023 lúc 13:52
a) Thực hiện phép tính
( 1 - 1/2 ) x ( 1 - 1/3 ) x ( 1 - 1/4 ) x ( 1 - 1/5 ) x ... x ( 1 - 1/99 )
b) Tìm X biết
( X +1/2 ) + ( X +1/6 ) + ( X +1/12 ) + ( X +1/20 ) + ... + ( X +1/90 ) = 99/10
2 x - 1/6 + 1/12 +1/20+...+1/90 = 3/11
(1/2+1/6+1/12+1/20+...+1/90) x 100 = ?
2*x+1/2*x + 6*x+1/6*x +12*x+1/12*x +20*x+1/20*x= 5.tìm x
a) N = 1/2 + 1/6+ 1/12 + 1/20 + 1/30 +1/42 + 1/56 + 1/72 +1/90
b) 5/8 + 2/9 -2/5 + 3/8 + 4/9 + 1/3 - 3/5 =
c) 4 1/5 + 5 1/3 - 2 2/3 x 3 1/5 + 9/25 : 9/20 =
Tìm y biết:
(Y-1/2):(1/2+1/6+1/12+1/20+...+1/90)=1/3
Tìm y biết: (y- \(\dfrac{1}{2}\)): (\(\dfrac{1}{2}\)+ \(\dfrac{1}{6}\) + \(\dfrac{1}{12}\) + \(\dfrac{1}{20}\)+ ... + \(\dfrac{1}{90}\)) = \(\dfrac{1}{3}\)
Bài 1 :
S1= 1/6 + 1/12 + 1/20 + 1/42 + ...........+ 1/90 + 1/110
S2 = 1/2.15 + 1/15.3 + 1/3.21 + ............+ 6/87.90
Bài 2:
1) x . 5 + x : 100 = 25,-5
2) ( x-7 ) . ( 4x -8 ) = 0
3) 1/1/35 : (1/5 – 1/7 ) – 3/ 3x-2 = 1/1/14: ( 1/2 -1/7)
4 )1/1/3 + 1/6 + 1/10 + ……. + 2/ x.(x+1) = 16/9