\(\dfrac{3}{x}=\dfrac{1}{y}=\dfrac{6}{2}\)

\(\Rightarrow\dfrac{3}{x}=\dfrac{1}{y}=3\)

\(\Rightarrow\left\{{}\begin{matrix}x=1\\y=\dfrac{1}{3}\end{matrix}\right.\)

x = 1

y = 1/3

x = 1 

y = 1/3. 

Ta có : 

\(\left(\frac{3}{4}x-\frac{1}{2}\right)^2-\frac{1}{64}=0\)

\(\Leftrightarrow\)\(\left(\frac{3}{4}x-\frac{1}{2}\right)^2=\frac{1}{64}\)

\(\Leftrightarrow\)\(\left(\frac{3}{4}x-\frac{1}{2}\right)^2=\frac{1^2}{8^2}\)

\(\Leftrightarrow\)\(\left(\frac{3}{4}x-\frac{1}{2}\right)^2=\left(\frac{1}{8}\right)^2\)

\(\Leftrightarrow\)\(\frac{3}{4}x-\frac{1}{2}=\frac{1}{8}\)

\(\Leftrightarrow\)\(\frac{3}{4}x=\frac{1}{8}+\frac{1}{2}\)

\(\Leftrightarrow\)\(\frac{3}{4}x=\frac{5}{8}\)

\(\Leftrightarrow\)\(x=\frac{5}{8}:\frac{3}{4}\)

\(\Leftrightarrow\)\(x=\frac{5}{8}.\frac{4}{3}\)

\(\Leftrightarrow\)\(x=\frac{5}{2}.\frac{1}{3}\)

\(\Leftrightarrow\)\(x=\frac{5}{6}\)

Vậy \(x=\frac{5}{6}\)

Chúc bạn học tốt ~ 

\(\left(\frac{3}{4}.x-\frac{1}{2}\right)^2-\frac{1}{64}=0\)

\(\left(\frac{3}{4}.x-\frac{1}{2}\right)^2=0+\frac{1}{64}=\frac{1}{64}\)

\(\left(\frac{3}{4}.x-\frac{1}{2}\right)^2=\left(\frac{1}{8}\right)^2\)

=>\(\frac{3}{4}.x-\frac{1}{2}=\frac{1}{8}\)

\(\frac{3}{4}.x=\frac{1}{8}+\frac{1}{2}\)

\(\frac{3}{4}.x=\frac{5}{8}\)

\(x=\frac{5}{8}:\frac{3}{4}\)

\(x=\frac{5}{6}\)

=> \(\left(\frac{3}{4}x-\frac{1}{2}\right)^2=\frac{1}{64}\)

Mà \(\frac{1}{64}=\left(\frac{1}{8}\right)^2=\left(\frac{-1}{8}\right)^2\)

+ Với \(\left(\frac{3}{4}x-\frac{1}{2}\right)^2=\left(\frac{1}{8}\right)^2\)

=> \(\frac{3}{4}x-\frac{1}{2}=\frac{1}{8}\)

=> \(\frac{3}{4}x=\frac{1}{8}+\frac{1}{2}\)

=> \(\frac{3}{4}x=\frac{2}{16}+\frac{8}{16}\)

=> \(\frac{3}{4}x=\frac{5}{8}\)

=> x = \(\frac{5}{8}:\frac{3}{4}\)

=> x = \(\frac{5}{6}\)

+ Với

=>

=>

=>

=>

=> x = \(\frac{1}{2}\)

Vậy x = 1/2 hoặc x = 5/6

\(xy\left(x-y\right)+yz\left(y-z\right)+zx\left(z-x\right)=x^2y-xy^2+y^2z-yz^2+z^2z-zx^2=x^2\left(y-z\right)+y^2\left(z-x\right)+z^2\left(z-y\right)\)

\(x^2\left(y-z\right)-y^2\left(x-z\right)-z^2\left(y-z\right)=\left(y-z\right)\left(x-z\right)\left(x+z\right)-y^2\left(x-z\right)=\left(x-z\right)\left(xy-yz-zx-z^2-y^2\right)\)

t cx k bt có đúng hay k đâu nha, nhớ xem kĩ lại

1) \(\dfrac{1}{27}+a^3=\left(\dfrac{1}{3}+a\right)\left(\dfrac{1}{9}-\dfrac{a}{3}+a^2\right)\)

2) \(=\left(2x+3y\right)\left(4x^2-6xy+9y^2\right)\)

3) \(=\left(\dfrac{1}{2}x+2y\right)\left(\dfrac{1}{4}x-xy+4y^2\right)\)

4) \(=\left(x^2+1\right)\left(x^4-x^2+1\right)\)

5) \(=\left(x^3+1\right)\left(x^6-x^3+1\right)\)

6) \(=\left(x-4\right)\left(x^2+4x+16\right)\)

7) \(=\left(x-5\right)\left(x^2+5x+25\right)\)

8) \(=\left(2x^2-3y\right)\left(4x^4+6x^2y+9y^2\right)\)

9) \(=\left(\dfrac{1}{4}x^2-5y\right)\left(\dfrac{1}{16}x^4+\dfrac{5}{4}x^2y+25y^2\right)\)

10) \(=\left(\dfrac{1}{2}x-2\right)\left(\dfrac{1}{4}x^2+x+4\right)\)

11) \(=\left(x+2\right)^3\)

12) \(=\left(x+3\right)^3\)

cần gấp lắm ạ xin các bạn giúp đỡ . ___ .

Câu 1: 

0,9 x 218 x 2 + 0,18 x 4290 + 0,6 x 353 x 3

= 9/10 x 436 + 9/50 x 4290 + 6/10 x 1059

= 9 x 43,6 + 9 x 85,8 + 6 x 105,9

= 3 x 130,8 + 3 x 257,4 + 3 x 211,8

= 3 x ( 130,8 + 257,4 + 211,8 )

= 3 x 600 

= 1800

Câu 2: 

3/4 x X + 1/2 x X - 15 = 35

X x ( 3/4 + 1/2 ) - 15 = 35

X x ( 3/4 + 1/2 ) = 50

X x 5/4 = 50

X = 40

VẬy X = 40

1.  0.9x218x2+0.18x4290+0.6x353x3  

= 1.8x218+0.18x10x429+1.8x353

=1.8x218+1.8x429+1.8x353

= 1.8x( 218+429+353 )

= 1.8x1000

=1800

2. 

3/4 x X + 1/2 x X - 15 = 35

3/4 x X + 1/2 x X = 35+15

3/4 x X +1/2 x X = 50

X x ( 3/4 + 1/2 ) = 50 

X x 5/4 = 50 

X = 50 : 5/4

X =40

đáp số cuối cùng là 0 vì 1-1/4 = 0/4 = 0 x cho những số nào khác cũng bằng 0 thôi

\(\left(1-\frac{1}{4}\right)\times\left(1-\frac{1}{9}\right)\times\left(1-\frac{1}{16}\right)\times...\times\left(1-\frac{1}{10000}\right)\)

\(=\frac{3}{4}\times\frac{8}{9}\times\frac{15}{16}\times...\times\frac{999}{10000}\)

\(=\frac{1\times3}{2\times2}\times\frac{2\times4}{3\times3}\times\frac{3\times5}{4\times4}\times...\times\frac{99\times101}{100\times100}\)

\(=\frac{1}{2}\times\frac{101}{100}\)

\(=\frac{101}{200}\)

Chu Nguyen Nhan sai rồi nhé 1-1/4 mà bằng 0 à        Học lại đê