Question

bài 1 tìm x; ( 1/15+ 1/35+ 1/63) * x=1

                   ( 1/2+1/4+1/8+1/16) : x=1/2+1/6+1/12+1/20+........+1/132

                   (1- 1/2)* (1-1/3)* (1-1/4)*......*(1-1/x)=0,01

Answer 1

câu 1 tớ biết bằng 9 bạn ạ 

Answer 2

bai 1 la 9

bai 2 la 18

bai 3 la 15

minh ko biet nua sai thi thoi

Answer 3

delllllllllllllllllllllllllllllllllllllllll

Answer 4

Ta có:

(1/2 + 1/4 + 1/8 + 1/16) = 8/16 + 4/16 + 2/16 + 1/16 = 15/16.

1/2 + 1/6 + 1/12 + 1/20 +…+ 1/132 = 1/(1.2) + 1/(2.3) + 1/(3.4) + 1/(4.5) +…+1/(11.12)

= (1 – 1/2) + (1/2 – 1/3) + (1/3 – 1/4) + (1/4 – 1/5) +…+ (1/11 – 1/12)

= 1 – 1/12 = 11/12

Vậy x = (15/16) : (11/12) = 45/44.