Bài 1:

1. \(x-8=3-2\left(x+4\right)\)

\(x-8=3-2x-8\)

\(3x=3\Rightarrow x=1\)

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

\(2x+6-3x+3=2\)

\(-x+9=2\Rightarrow x=7\)

3. \(4\left(x-5\right)-\left(3x-1\right)=x-19\)

\(4x-20-3x+1=x-19\)

\(0x=0\Rightarrow x=0\)

4. \(7-\left(x-2\right)=5\left(2x-3\right)\)

\(7-x+2=10x-15\)

\(-11x=-24\Rightarrow x=\frac{24}{11}\)

5. \(32-4\left(0,5y-5\right)=3y+2\)

\(32-2y+20=3y+2\)

\(-5y=-50\Rightarrow y=10\)

6. \(3\left(x-1\right)-x=2x-3\)

\(3x-3-x=2x-3\)

\(0x=0\Rightarrow x=0\)

Bài 2:

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

\(\frac{\left(2-x\right)5}{15}-\frac{\left(3-2x\right)3}{15}=0\)

\(\frac{10-5x-9+6x}{15}=0\)

\(x+1=0\Rightarrow x=-1\)

2. \(\frac{3-4x}{4}=\frac{x+2}{5}\)

\(\frac{5\left(3-4x\right)}{20}-\frac{4\left(x+2\right)}{20}=0\)

\(\frac{15-20x-4x-8}{20}=0\)

\(7-24x=0\)

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

Câu 1 : 

a, \(\frac{3\left(2x+1\right)}{4}-\frac{5x+3}{6}=\frac{2x-1}{3}-\frac{3-x}{4}\)

\(\Leftrightarrow\frac{6x+3}{4}+\frac{3-x}{4}=\frac{2x-1}{3}+\frac{5x+3}{6}\)

\(\Leftrightarrow\frac{5x+6}{4}=\frac{9x+1}{6}\Leftrightarrow\frac{30x+36}{24}=\frac{36x+4}{24}\)

Khử mẫu : \(30x+36=36x+4\Leftrightarrow-6x=-32\Leftrightarrow x=\frac{32}{6}=\frac{16}{3}\)

tương tự 

\(\frac{19}{4}-\frac{2\left(3x-5\right)}{5}=\frac{3-2x}{10}-\frac{3x-1}{4}\)

\(< =>\frac{19.5}{20}-\frac{8\left(3x-5\right)}{20}=\frac{2\left(3-2x\right)}{20}-\frac{5\left(3x-1\right)}{20}\)

\(< =>95-24x+40=6-4x-15x+5\)

\(< =>-24x+135=-19x+11\)

\(< =>5x=135-11=124\)

\(< =>x=\frac{124}{5}\)

\(\frac{\left(x-2\right).3}{2}+3+\frac{\left(x-3\right).5}{3}+5+\frac{\left(x-5\right).2}{5}+2=10\)

\(< =>\frac{\left(x-2\right).3.15}{30}+\frac{\left(x-3\right).5.10}{30}+\frac{\left(x-5\right).2.6}{30}=10-2-3-5\)

\(< =>\frac{\left(x-2\right).45+\left(x-3\right).50+\left(x-5\right).12}{30}=0\)

\(< =>45x-90+50x-150+12x-60=0\)

\(< =>107x-300=0< =>x=\frac{300}{107}\)

1,\(x-8=3-2\left(x+4\right)\)

\(\Leftrightarrow\)\(x-8=3-2x-8\)

\(\Leftrightarrow x-8-3+2x+8=0\)

\(\Leftrightarrow3x-3=0\)

\(\Leftrightarrow3x=3\)

\(\Leftrightarrow x=1\)

Vậy \(S=\left\{1\right\}\)

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

\(\Leftrightarrow2\left(x+3\right)-3\left(x-1\right)-2=0\)

\(\Leftrightarrow2x+6-3x+3-2=0\)

\(\Leftrightarrow-x+7=0\) \(\Leftrightarrow-x=-7\)

\(\Leftrightarrow x=7\)

Vậy \(S=\left\{1\right\}\)

3,\(4\left(x-5\right)-\left(3x-1\right)=x-19\)

\(\Leftrightarrow4x-20-3x+1-x+19=0\)

\(\Leftrightarrow0x+0=0\) (pt vô số nghiệm)

Vậy S=R

4,\(7-\left(x-2\right)=5\left(2x-3\right)\)

\(\Leftrightarrow7-x+2-10x+15=0\)

\(\Leftrightarrow24-11x=0\)

\(\Leftrightarrow11x=24\)

\(\Leftrightarrow x=\frac{24}{11}\)

Vậy \(S=\left\{\frac{24}{11}\right\}\)

x2x2 là sao bn

Tìm x, biết:

1) 2x ( x - 5)  - x ( 2x - 4 ) = 15

<=> 2x² - 10x - 2x² + 4x - 15 = 0

<=> -6x - 15 = 0

<=> -6x = 15

<=> x = -15/6

2)  ( x +1)( x + 2 ) - ( x + 4 ) ( x + 3 ) = 6

<=> x² + 2x + x + 2 - x² - 3x - 4x - 12 - 6 = 0

<=> -4x = -16

<=> x = 4

3)  4x² - 4x + 5 - x ( 4x - 3) = 1 - 2x

<=> 4x² - 4x + 5 - 4x² + 3x - 1 + 2x = 0

<=> x + 4 = 0

<=> x = -4

4) ( x + 3 ) ( 2x + 1 ) - 2x² = 4x - 5

<=> 2x² + x + 6x + 3 - 2x² - 4x + 5 = 0

<=> 3x + 8 = 0

<=> 3x = -8

<=> x = -8/3

5) -4 ( 2x - 8 ) + ( 2x - 1 )( 4x + 3 ) = 0

<=> - 8x + 32 + 8x² + 6x - 4x - 3 = 0

.......

6) -3 . (x-2) + 4 . (2x-6) - 7 . (x-9)= 5 . (3-2)

<=> -3x + 6 + 8x - 24 - 7x + 63 - 5 = 0

<=> -2x + 40 = 0

<=> -2x = -40

<=> x = 20

Còn lại tương tự ....

1)2x^2-10x-2x^2+14x=15

4x=15

x=15/4

x=-15/6