thanks bro ! :)

tích cho mk đi bro

a) 2012 x 8 - 8 x 2011

= 8 x (2012 - 2011)

= 8 x 1 

= 8

b) \(\frac{7}{8}.2\frac{2}{3}-\frac{5}{8}.2\frac{2}{3}\)

\(=\frac{7}{8}.\frac{8}{3}-\frac{5}{8}.\frac{8}{3}\)

\(=\frac{8}{3}.\left(\frac{7}{8}-\frac{5}{8}\right)\)

\(=\frac{8}{3}.\frac{2}{8}\)

\(=\frac{16}{6}=\frac{8}{3}\)

1,

a,\(2012.8-8.2011\)

\(=8\left(2012-2011\right)\)

\(=8.1\)

\(=8\)

b.\(\frac{7}{8}.2\frac{2}{3}-\frac{5}{8}.2\frac{2}{3}\)

\(=2\frac{2}{3}.\left(\frac{7}{8}-\frac{5}{8}\right)\)

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

\(=\frac{2}{3}\)

\(8-12x+6x^2-x^3\)

\(=\left(2-x\right)^3\)

\(125x^3-75x^2+15x-1\)

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

\(x^2-xz-9y^2+3yz\)

\(=\left(x-3y\right)\left(x+3y\right)-z\left(x-3y\right)\)

\(=\left(x-3y\right)\left(x+3y-z\right)\)

\(x^3-x^2-5x+125\)

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

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

\(=\left(x+5\right)\left(x^2-6x+25\right)\)

\(x^3+2x^2-6x-27\)

\(=x^3+5x^2+9x-3x^2-15x-27\)

\(=x\left(x^2+5x+9\right)-3\left(x^2+5x+9\right)\)

\(=\left(x-3\right)\left(x^2+5x+9\right)\)

\(12x^3+4x^2-27x-9\)

\(=4x^2\left(3x+1\right)-9\left(3x+1\right)\)

\(=\left(3x+1\right)\left(4x^2-9\right)\)

\(=\left(3x+1\right)\left(2x-3\right)\left(2x+3\right)\)

\(4x^4+4x^3-x^2-x\)

\(=4x^3\left(x+1\right)-x\left(x+1\right)\)

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

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

Là 00000000000000

a) \(1\frac{5}{8}:x-1\frac{1}{4}=2\)

=> \(\frac{13}{8}:x-\frac{5}{4}=2\)

=> \(\frac{13}{8}:x=\frac{13}{4}\)

=> \(x=\frac{13}{8}:\frac{13}{4}=\frac{13}{8}\cdot\frac{4}{13}=\frac{1}{2}\)

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

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

=> x không thỏa mãn 

c) 2(x - 1) = 3x + 1

=> 2x - 2 = 3x + 1

=> 2x - 2 - 3x - 1 = 0

=> 2x - 3x - 2 - 1 = 0

=> -x = 3

=> x = -3

d) \(\frac{-2}{x}=\frac{x}{-8}\)=> x² = 16 => x = \(\pm\)4

e) |7 - x| + 2x = 11

=> |7 - x| = 11 - 2x

=> 7 - x = 11 - 2x

=> 7 - x - 11 + 2x = 0

=> 7 - 11 - x + 2x = 0

=> -4 + x = 0

=> -4 = -x

=> x = 4

a)=> 13/8 : x-5/4 =2

<=> 13/8 : x= 13/4

<=> x=1/2

b)=>x² - (1/3)² = 1/2

=>x²-1/9=1/2

=>x²=11/18

=>x=0.78 (bằng xấp xỉ thôi nhé bạn :33)

c)=>2x-2=3x-1

=>2x-3x=2-1

=>-x=1

=>x=-1

còn 2 câu bạn làm nốt nhé :33

k đúng cho mk nhé!!!!

a. \(\frac{x+1}{2}=\frac{8}{x+1}\)

\(\Leftrightarrow\left(x+1\right).\left(x+1\right)=8.2\)

\(\Leftrightarrow\left(x+1\right)^2=16\)

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

\(\Leftrightarrow\left(x+1\right)=2^2\)

\(\Leftrightarrow\left(x+1\right)=4\)

\(\Leftrightarrow x=4-1=3\)

b. \(x:\left(9\frac{1}{2}-\frac{3}{2}\right)=\frac{0,4+\frac{2}{9}-\frac{2}{11}}{1,6+\frac{8}{9}-\frac{8}{11}}\)

\(\Leftrightarrow x:\left(\frac{10}{2}-\frac{3}{2}\right)=\frac{0,4+0,2-0,18}{1,6+0,8-0,72}\)

\(\Leftrightarrow x:\frac{7}{2}=\frac{\frac{21}{50}}{\frac{42}{25}}\)

\(\Leftrightarrow x=\frac{\frac{21}{50}}{\frac{42}{25}}.\frac{7}{2}\Leftrightarrow x=\frac{1}{4}.\frac{7}{2}=\frac{7}{8}\)

a )  \(\frac{x+1}{2}=\frac{8}{x+1}\)

\(\Rightarrow\left(x+1\right).\left(x+1\right)=2.8\)

\(\Rightarrow\left(x+1\right)^2=16\)

\(\Rightarrow\orbr{\begin{cases}x+1=4\\x+1=-4\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=4-1\\x=-4-1\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=3\\x=-5\end{cases}}\)

Dấu " \(\orbr{\begin{cases}\\\end{cases}}\)là hoặc nha !!! 

\(x^2-0,25=0\)

\(\Leftrightarrow x^2-0,5^2=0\)

\(\Leftrightarrow x-0,5=0\)

\(\Leftrightarrow x=0+0,5\)

\(\Leftrightarrow x=0,5\)

b.

\(\dfrac{8}{2x}=2\Leftrightarrow2x=\dfrac{8}{2}\Rightarrow x=4:2=2\)

c.

\(\left(2x-1\right)^3=8\)

\(\Rightarrow\left(2x-1\right)^3=2^3\)

\(\Rightarrow2x-1=2\)

\(\Rightarrow2x=2+1\)

\(\Rightarrow2x=3\)

\(\Rightarrow x=\dfrac{3}{2}\)

d.

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

\(\Rightarrow x-2=4\)

\(\Rightarrow x=4+2\)

\(\Rightarrow x=6\)

Chúc bạn học tốt!!!!

\(x^2-0,25=0\)

\(\Rightarrow x^2=0,25\)

\(\Rightarrow x=0,5\)

b. \(\dfrac{8}{2x}=2\)

\(\Rightarrow2x=4\)

\(\Rightarrow x=2\)

c. \(\left(2x-1\right)^3=8\)

\(\left(2x-1\right)^3=2^3\)

\(\Rightarrow2x-1=2\)

\(\Rightarrow x=\dfrac{3}{2}\)

d. \(\left(x-2\right)^2=16\)

\(\left(x-2\right)^2=\pm4^2\)

\(\Rightarrow\left[{}\begin{matrix}x-2=4\\x-2=-4\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=6\\x=-2\end{matrix}\right.\)

a) \(\frac{x-3}{3}-1=\frac{x}{-4}\)

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

\(\Leftrightarrow\frac{x-6}{3}=\frac{x}{-4}\)

\(\Leftrightarrow-4\left(x-6\right)=3x\)

\(\Leftrightarrow-4x+24=3x\)

\(\Leftrightarrow24=3x+4x\)

\(\Leftrightarrow7x=24\)

\(\Leftrightarrow x=\frac{24}{7}\)

b) \(\frac{5}{8}-\left(x-\frac{1}{2}\right)=\frac{-3}{4}\)

\(\Leftrightarrow\frac{5}{8}-x+\frac{1}{2}=\frac{-3}{4}\)

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

\(\Leftrightarrow\frac{9}{8}-x=\frac{-3}{4}\)

\(\Leftrightarrow x=\frac{9}{8}+\frac{3}{4}\)

\(\Leftrightarrow x=\frac{15}{8}\)