Trả lời 

\(\frac{1}{4}.\frac{2}{6}.\frac{3}{8}.\frac{4}{10}.....\frac{30}{62}.\frac{31}{64}=2^x\)

\(\Leftrightarrow\frac{1}{2.2.2....2.64}=2^x\) ( 30 số hạng 2 ) 

\(\Leftrightarrow\frac{1}{2^{30}.2^6}=2^x\)

\(\Leftrightarrow\frac{1}{2^{36}}=2^x\)

\(\Rightarrow2^x=2^{-36}\)

\(\Rightarrow x=-36\)

Vậy \(x=-36\)

H = 1/4 . 2/6 . 3/8 . 4/10. ... . 30/62 . 31/64

H= 1/2.2 . 2/2.3 . 3/2.4 . 4/2.5 . ... . 30/2.31 . 31/2.32

H = 1/2 . 1/2 . 1/2 . 1/2 . ... . 1/2 . 1/32 (31 số 1/2)

H = 1/2^31 . 1/2^5

H = 1/2^36

Vậy H = 1/2^36

(1.2.3.4.5....31)/(2(1.2.3.4.5.....31).64)=2^x

1/(2.64)=2^x

1/128=2^x

2^-7=2^x

=>x=-7

cảm ơn bạn

\(\Leftrightarrow\dfrac{2\cdot3\cdot...\cdot31}{\left(2\cdot3\cdot...\cdot31\right)\cdot\left(2\cdot2\cdot...\cdot2\right)\cdot2^6}=2^x\)

=>2^x=1/2^36

=>x=-36