a. \(x\left(x^2-25\right)-\left(x^3-2x^2+4x+2x^2-4x+8\right)=17\)

\(x^3-25x-\left(x^3+8\right)=17\)

\(x^3-25x-x^3-8=17\)

\(-25x=25\)

\(x=-1\)

c. \(6x^2-\left(6x^2-4x+15x-10\right)=7\)

\(6x^2-6x^2-11x+10=7\)

\(-11x=-3\)

\(x=\frac{3}{11}\)

d.\(x^2-4x-x^2+8=0\)

\(-4x=-8\)

\(x=2\)

Bài 2: 

a: =a-b+c+a-c+b-b

=2a-b

b: =2x-5+x-a+x-5-a

=4x-10-2a

`a,4x-10=0   `

`<=> 4x=10`

`<=>x=10/4`

`<=>x=5/2`

`b, 7-3x=9-x     `

`<=>-3x+x=9-7`

`<=>-2x=2`

`<=>x=-1`

`c, 2x-(3-5x) = 4(x+3)`

`<=>2x-3+5x=4x+12`

`<=>2x+5x-4x=12+3`

`<=>3x=15`

`<=>x=5`

`d, 5-(6-x)=4(3-2x)     `

`<=>5-6+x=12-8x`

`<=>x+8x=12-5+6`

`<=>9x=13`

`<=>x=13/9`

`e, 4(x+3)=-7x+17   `

`<=>4x+12=-7x+17`

`<=>4x+7x=17-12`

`<=>11x=5`

`<=>x=5/11`   

`f, 5(x-3) - 4=2(x-1)+7`

`<=>5x-15-4=2x-2+7`

`<=>5x-2x=15+4-2+7`

`<=>3x=24`

`<=>x=8`

`g, 5(x-3)-4=2(x-1)+7       `

`<=>5x-15-4=2x-2+7`

`<=>5x-2x=15+4-2+7`

`<=>3x=24`

`<=>x=8`

`h,4(3x-2)-3(x-4)=7x+20`

`<=>12x-8-3x+12=7x+20`

`<=>12x-3x-7x=20+8+12`

`<=>2x=40`

`<=>x=20`

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

=> x² + 3x - 2x - 6 = 6

=> x² + x - 6 - 6 = 0

=> x² + x - 12 = 0

=> x² + 4x - 3x - 12 = 0

=> x(x + 4) - 3(x + 4) = 0

=> (x - 3)(x + 4) = 0

=> \(\orbr{\begin{cases}x-3=0\\x+4=0\end{cases}}\)

=> \(\orbr{\begin{cases}x=3\\x=-4\end{cases}}\)

b) (2x - 3)(x + 2) = 4

=> 2x² + 4x - 3x - 6 = 4

=> 2x² + x - 6 - 4 = 0

=> 2x² + x - 10 = 0

=> 2x² + 5x - 4x - 10 = 0

=> x(2x + 5) - 2(2x + 5) = 0

=> (x - 2)(2x + 5) = 0

=> \(\orbr{\begin{cases}x-2=0\\2x+5=0\end{cases}}\)

=> \(\orbr{\begin{cases}x=2\\x=-\frac{5}{2}\end{cases}}\)

a) \(x\left(x-4\right)-\left(x^2-8\right)=0\)

\(\Leftrightarrow x^2-4x-x^2+8=0\)

\(\Leftrightarrow-4\left(x-2\right)=0\)

\(\Leftrightarrow x-2=0\)

\(\Leftrightarrow x=2\)

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

\(\Leftrightarrow3x^2-3x+2x-2-3\left(x^2-2x+x-2\right)=0\)

\(\Leftrightarrow3x^2-3x+2x-2-3x^2+6x-3x+6=0\)

\(\Leftrightarrow2x=-4\)

\(\Leftrightarrow x=-2\)

c) \(x\left(x+5\right)\left(x-5\right)-\left(x+2\right)\left(x^2-2x+4\right)=17\)

\(\Leftrightarrow x\left(x^2-25\right)-\left(x^3+8\right)=17\)

\(\Leftrightarrow x^3-25x-x^3-8=17\)

\(\Leftrightarrow-25x=25\)

\(\Leftrightarrow x=-1\)

a) x(x - 4 ) - ( x^2 - 8 ) = 0

=>x²-4x-x²+8=0

=>8-4x=0

=>4x=8

=>x=2

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

=>3x²-x-2-3x²+3x+6=4

=>2x+4=4

=>2x=0

=>x=0

c) x( x + 5 )( x - 5 ) - ( x + 2 )( x^2 - 2x + 4 ) = 17

=>x(x²-25)-(x³+8)=17

=>x³-25x-x³-8=17

=>-25x-8=17

=>-25x=25

=>x=-1

bạn tách một câu vài câu hỏi chứ đừng gộp như thế này ko ai trả lời đâu

a: =>\(4x-5=2x-2+x=3x-2\)

=>x=3

b: \(\Leftrightarrow7x-35=3x+6\)

=>4x=41

=>x=41/4

c: =>(2x+5)(x+5)-2x^2=0

=>2x^2+10x+5x+25-2x^2=0

=>15x=-25

=>x=-5/3

e: \(\Leftrightarrow\dfrac{11}{x}=\dfrac{9x-36+2x+2}{\left(x+1\right)\left(x-4\right)}\)

=>11(x^2-3x-4)=x(11x-34)

=>11x^2-33x-44=11x^2-34x

=>x=44

a) \(\dfrac{2}{3}x-\dfrac{1}{2}=\dfrac{1}{10}\)

\(\dfrac{2}{3}x=\dfrac{1}{10}+\dfrac{1}{2}=\dfrac{3}{5}\)

\(x=\dfrac{3}{5}:\dfrac{2}{3}=\dfrac{9}{10}\)

b) \(\dfrac{39}{7}:x=13\)

\(x=\dfrac{\dfrac{39}{7}}{13}=\dfrac{3}{7}\)

c) \(\left(\dfrac{14}{5}x-50\right):\dfrac{2}{3}=51\)

\(\dfrac{14}{5}x-50=51\cdot\dfrac{2}{3}=34\)

\(\dfrac{14}{5}x=34+50=84\)

\(x=\dfrac{84}{\dfrac{14}{5}}=30\)

d) \(\left(x+\dfrac{1}{2}\right)\left(\dfrac{2}{3}-2x\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{1}{2}=0\\\dfrac{2}{3}-2x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)

e) \(\dfrac{2}{3}x-\dfrac{1}{2}x=\dfrac{5}{12}\)

\(\dfrac{1}{6}x=\dfrac{5}{12}\)

\(x=\dfrac{5}{12}:\dfrac{1}{6}=\dfrac{5}{2}\)

g) \(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\dfrac{11}{5}-\dfrac{3}{7}=-2\)

\(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\cdot\dfrac{11}{5}=-2+\dfrac{3}{7}=-\dfrac{11}{7}\)

\(x\cdot\dfrac{44}{7}+\dfrac{3}{7}=-\dfrac{11}{7}:\dfrac{11}{5}=-\dfrac{5}{7}\)

\(\dfrac{44}{7}x=-\dfrac{5}{7}-\dfrac{3}{7}=-\dfrac{8}{7}\)

\(x=-\dfrac{8}{7}:\dfrac{44}{7}=-\dfrac{2}{11}\)

h) \(\dfrac{13}{4}x+\left(-\dfrac{7}{6}\right)x-\dfrac{5}{3}=\dfrac{5}{12}\)

\(\dfrac{25}{12}x-\dfrac{5}{3}=\dfrac{5}{12}\)

\(\dfrac{25}{12}x=\dfrac{5}{12}+\dfrac{5}{3}=\dfrac{25}{12}\)

\(x=1\)

Mỏi tay woa bn làm nốt nha!!