1,53  x 72 + 15,3 x 5,2 + 1,53 x 22 - 1,53 x 46

= 110,16 + 79,56 + 33,66 - 70,38

= 153

hok tốt !

1 , 53 x 72 + 15 , 3 x 5 , 2 + 1 , 53  x 22 - 1 , 53 x 46 

= 1 , 53 x 72 + 1 , 53 x 10 x 5 , 2 + 1 , 53 x 22 - 1 , 53 x 46 

= 1 , 53 x 72 + 1 , 53 x 52 + 1 , 53 x 22 - 1 , 53 x 46 

= 1 , 53 x ( 72 + 52 + 22 - 46 ) 

= 1 , 53 x (  146 - 46 ) 

= 1 , 53 x 100 

= 153 

Chúc bạn học tốt !!! 

= 1,53 x 72 + 1,53 x 10 x 5,2 + 1,53 x 22 - 1,53 x 46

= 1,53 x 72 + 1,53 x 52 + 1,53 x 22 - 1,53 x 46

= 1,53 x ( 72 + 52 + 22 - 46)

= 1,53 x  100

=  153 

K NHA .Ko tk mất công mình làm cho bạn đó

a=2.54901-594901+2009

=54901+2009=56910

mk chi giup dc cau a thoi nha

1.53*82+8.2*1.53+10*1.53*22-1.53*86

=1.53(82+8.2+220-86)

=1.53*224.2

=343 026

a) 2,54901 - (1,54901 - 2009)

= 2,54901 - 1,54901 + 2009

= 54901 + 2009 

= 56910

b) 1,53 x 82 +8,2 x1,53 + 10 x 1,53 x 22- 1,53 x 86 

= 1,53 x 82 + 8,2 x1,53 + 220 x 1,53 - 1,53 x 86 

= 1,53 x (82 + 8,2 + 220 - 86)

= 1,53 x 224.2

= 343.026

Giải

1/(2.4) + 1/(4.6) + … + 1/[(2x – 2).2x] = 1/8
=> 2/(2.4) + 2/(4.6) + ...+ 2/[(2x - 2).2x] = 2/8
 =>1-1/4+1/4-1/6+...+1/(2x-2) - 1/2x = 2/8
 =>1 - 1/2x = 2/8
 =>1/2x = 1 - 2/8
 =>1/2x = 6/8 = 3/4
=>1.4 = 2.x.3
=>4 = 6x
=> x thuộc rỗng
 Vậy x thuộc rỗng

\(\frac{1}{2\cdot4}+\frac{1}{4\cdot6}+...+\frac{1}{\left(2x-2\right)\cdot2x}=\frac{1}{8}\)

\(\Rightarrow\frac{2}{2\cdot4}+\frac{2}{4\cdot6}+...+\frac{2}{\left(2x-2\right)\cdot2x}=\frac{2}{8}\)

\(\Rightarrow\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+...+\frac{1}{2x-2}-\frac{1}{2x}=\frac{1}{4}\)

\(\Rightarrow\frac{1}{2}-\frac{1}{2x}=\frac{1}{4}\)

\(\Rightarrow\frac{1}{2x}=\frac{1}{2}-\frac{1}{4}\)

\(\Rightarrow\frac{1}{2x}=\frac{1}{4}\)

\(\Rightarrow2x=4\)

\(\Rightarrow x=2\)

\(\frac{1}{2.4}\)\(\)

\(\Leftrightarrow\dfrac{2}{2.4}+\dfrac{2}{4.6}+...+\dfrac{2}{\left(2x-2\right).2x}=\dfrac{11}{24}\)

\(\Leftrightarrow\dfrac{4-2}{2.4}+\dfrac{6-4}{4.6}+...+\dfrac{2x-\left(2x-2\right)}{\left(2x-2\right).2x}=\dfrac{11}{24}\)

\(\Leftrightarrow\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{6}+...+\dfrac{1}{2x-2}-\dfrac{1}{2x}=\dfrac{11}{24}\)

\(\Leftrightarrow\dfrac{1}{2}-\dfrac{1}{2x}=\dfrac{11}{24}\)

\(\Leftrightarrow\dfrac{1}{2x}=\dfrac{1}{2}-\dfrac{11}{24}\)

\(\Leftrightarrow\dfrac{1}{2x}=\dfrac{1}{24}\)

\(\Rightarrow2x=24\)

\(\Rightarrow x=12\)

\(\text{Sửa đề:}\)

\(\frac{1}{2.4}+\frac{1}{4.6}+...+\frac{1}{\left(2x-2\right).2x}=\frac{1}{8}\)

\(\text{Đặt biểu thức là A:}\)

\(A=\frac{1}{2.4}+\frac{1}{4.6}+...+\frac{1}{\left(2x-2\right).2x}=\frac{1}{8}\)

\(2A=\frac{2}{2.4}+\frac{2}{4.6}+...+\frac{2}{\left(2x-2\right).2x}=\frac{1}{8}\times2=\frac{1}{4}\)

\(2A=\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+...+\frac{1}{2x-2}-\frac{1}{2x}=\frac{1}{4}\)

\(2A=\frac{1}{2}-\frac{1}{2x}=\frac{1}{4}\)

\(A=\frac{1}{2}\times\left(\frac{1}{2}-\frac{1}{2x}\right)=\frac{1}{8}\)

\(A=\frac{1}{2}\times\frac{1}{2}-\frac{1}{2}\times\frac{1}{2x}=\frac{1}{8}\)

\(A=\frac{1}{4}-\frac{1}{4x}=\frac{1}{8}\)

\(\Rightarrow\frac{1}{4x}=\frac{1}{4}-\frac{1}{8}=\frac{2}{8}-\frac{1}{8}=\frac{1}{8}\)

\(\Rightarrow4x=8\)

\(\Rightarrow x=8\div4=2\)

Đáp án C

1/(2.4) + 1/(4.6) + … + 1/[(2x – 2).2x] = 1/8
suy ra 2/(2.4) + 2/(4.6) + ...+ 2/[(2x - 2).2x] = 2/8
suy ra 1-1/4+1/4-1/6+...+1/(2x-2) - 1/2x = 2/8
suy ra 1 - 1/2x = 2/8
suy ra 1/2x = 1 - 2/8
suy ra 1/2x = 6/8 = 3/4
suy ra 1.4 = 2.x.3
suy ra 4 = 6x
suy ra x thuộc rỗng
 Vậy x thuộc rỗng
k cho mình nha. Chúc bạn học tốt!

Thanks you so much.

Thùy Anh tính sai rùi, dòng 2 phải nhân cả tử và mẫu cùng zới 2 mò, ko nhận ra ak mng ưi

\(x-\dfrac{1}{2}\left(\dfrac{2}{2.4}+\dfrac{2}{4.6}+...+\dfrac{2}{98.100}\right)=\dfrac{1}{100}\)

\(x-\dfrac{1}{2}\left(\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{6}+...+\dfrac{1}{98}-\dfrac{1}{100}\right)=\dfrac{1}{100}\)

\(x-\dfrac{1}{2}\left(\dfrac{1}{2}-\dfrac{1}{100}\right)=\dfrac{1}{100}\)

\(x=\dfrac{51}{200}\)