x(x+1)-(x-1)(x+2)=8

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

\(\Leftrightarrow0x=6\left(ptvn\right)\)

\(\Rightarrow S=\varnothing\)

\(x.2-5.x=0\)

\(\Rightarrow-3x=0\)

\(\Rightarrow x=0\)

Vậy \(x=0\)

\(2x-5x=0\)

\(=>2x=5x\)

\(=>x=0\)

\(\frac{x+2}{x-5}< 0\) <=> x+2 và x-5 trái dấu

Mà x+2 > x-5

Nên x+2 > 0 và x-5 < 0

=>x > -2 và x < 5

Vậy -2 <x <5

x.(x-5)+x-5=o

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

=>(x-5)(x+1)=0

=> x-5=0    =>x=5

     x+1=0        x=-1

x ( x - 5 ) + x -  5 = 0

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

(x - 5 ) ( x + 1 ) = 0

\(\Rightarrow\orbr{\begin{cases}x-5=0\\x+1=0\end{cases}\Rightarrow\orbr{\begin{cases}x=5\\x=-1\end{cases}}}\)

Vậy...

\(x.\left(x-5\right)+x-5=0\)

\(\Leftrightarrow x.\left(x-5\right)+\left(x-5\right)=0\)

\(\Leftrightarrow\left(x-5\right).\left(x+1\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x-5=0\\x+1=0\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=5\\x=-1\end{cases}}\)

Ta có :

 \(x-\dfrac{8}{5}< -6\\ \Rightarrow x< -6+\dfrac{8}{5}\\ \Rightarrow x< -\dfrac{22}{5}=-4\dfrac{2}{5}\\ \Rightarrow-6< x< -1\dfrac{2}{5}\\ \Rightarrow x=-5\)

    Vậy...

\(\Rightarrow\left\{{}\begin{matrix}x-\dfrac{8}{5}< -6\\-6< x\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}x< -6+\dfrac{8}{5}\\x>-6\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}x< -\dfrac{22}{5}\\x>-6\end{matrix}\right.\\ \Rightarrow-6< x< -\dfrac{22}{5}\)

X + 1+2+3+4+5-6-7-8-9=1-2-3-4-5+6+7+8+9

X+  (-15)                     =  17

X                                = 17-(-15)

X                                = 32

vậy x = 32 

tk nha

\(...\Rightarrow x+x+\dfrac{x}{43}+\dfrac{x}{8}=14+148+\dfrac{10}{30}+\dfrac{5}{95}\)

\(\Rightarrow\left(1+1+\dfrac{1}{43}+\dfrac{1}{8}\right)x=162+\dfrac{1}{3}+\dfrac{1}{19}\)

\(\Rightarrow\left(\dfrac{2.43.8}{43.8}+\dfrac{1.8}{43.8}+\dfrac{1.43}{43.8}\right)x=\dfrac{162.3.19}{3.19}+\dfrac{1.19}{3.19}+\dfrac{1.3}{19.3}\)

\(\Rightarrow\left(\dfrac{688}{344}+\dfrac{8}{344}+\dfrac{43}{344}\right)x=\dfrac{9234}{57}+\dfrac{19}{57}+\dfrac{3}{57}\)

\(\Rightarrow\dfrac{739}{344}x=\dfrac{9256}{57}\)

\(\Rightarrow x=\dfrac{9256}{57}:\dfrac{739}{344}=\dfrac{9256}{57}.\dfrac{344}{739}=\dfrac{\text{3184064}}{\text{42123}}\)

Vì x, y > 0

Đặt \(\frac{x}{5}=\frac{y}{4}=k\Rightarrow\hept{\begin{cases}x=5k\\y=4k\end{cases}}\)( k > 0 ) 

x² - y² = 4

<=> ( 5k )² - ( 4k )² = 4

<=> 25k² - 16k² = 4

<=> 9k² = 4

<=> k² = 4/9

<=> k = 2/3 ( vì k > 0 )

=> \(\hept{\begin{cases}x=5\cdot\frac{2}{3}=\frac{10}{3}\\y=4\cdot\frac{2}{3}=\frac{8}{3}\end{cases}}\)

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Ta có x/5=y/5=k
=>x=5k;y=4k
Theo tính chất dãy tỉ số = nhau ta có
x/5=y/4=x^2-y^2/5^2-4^2=4/9
x/5=4/9=>x=4/9.5=20/9
y/4=4/9=>y=4/9.4=16/9
=>x=20/9;y=16/9

Trả lời đúng , mình sẽ cho 5 vote

\(\Rightarrow x-\left(-x+x+3\right)-\left(x+3-x+2\right)=0\\ \Rightarrow x-3-5=0\\ \Rightarrow x=8\)

Sai rồi bạn ơi, bằng -2 mới đúng,bn thử lại coi