Bài 2: 

a: =>x=0 hoặc x+3=0

=>x=0 hoặc x=-3

b: =>x-2=0 hoặc 5-x=0

=>x=2 hoặc x=5

c: =>x-1=0

hay x=1

Bài 2: 

a: =>x=0 hoặc x=-3

b: =>x-2=0 hoặc 5-x=0

=>x=2 hoặc x=5

c: =>x-1=0

hay x=1

a) \(x\left(x-6\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=0\\x-6=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=0\\x=6\end{matrix}\right.\)

b) \(\left(-7-x\right)\left(-x+5\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}-7-x=0\\-x+5=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-7\\x=-5\end{matrix}\right.\)

c) \(\left(x+3\right)\left(x-7\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x+3=0\\x-7=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-3\\x=7\end{matrix}\right.\)

d) \(\left(x-3\right)\left(x^2+12\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x-3=0\\x^2+12=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=3\\x^2=-12\text{(vô lý)}\end{matrix}\right.\)

\(\Rightarrow x=3\)

e) \(\left(x+1\right)\left(2-x\right)\ge0\)

\(\Rightarrow\left[{}\begin{matrix}\left[{}\begin{matrix}x+1\ge0\\2-x\ge0\end{matrix}\right.\\\left[{}\begin{matrix}x+1\le0\\2-x\le0\end{matrix}\right.\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}\left[{}\begin{matrix}x\ge-1\\x\le2\end{matrix}\right.\\\left[{}\begin{matrix}x\le-1\\x\ge2\end{matrix}\right.\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}-1\le x\le2\\x\in\varnothing\end{matrix}\right.\)

\(\Rightarrow-1\le x\le2\)

f) \(\left(x-3\right)\left(x-5\right)\le0\)

\(\Rightarrow\left[{}\begin{matrix}\left[{}\begin{matrix}x-3\le0\\x-5\ge0\end{matrix}\right.\\\left[{}\begin{matrix}x-3\ge0\\x-5\le0\end{matrix}\right.\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}\left[{}\begin{matrix}x\le3\\x\ge5\end{matrix}\right.\\\left[{}\begin{matrix}x\ge3\\x\le5\end{matrix}\right.\end{matrix}\right.\)

\(\Rightarrow3\le x\le5\)

a) =>\(\left[{}\begin{matrix}x=0\\x-6=0\end{matrix}\right.=>\left[{}\begin{matrix}x=0\\x=6\end{matrix}\right.\)

b => \(\left[{}\begin{matrix}-7-x=0\\-x+5=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-7\\x=5\end{matrix}\right.\)

d) => \(\left[{}\begin{matrix}x-3=0\\x^2+12=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=3\\x^2=-12\end{matrix}\right.\)(vô lí) => x=3

c) => \(\left[{}\begin{matrix}x+3=0\\x-7=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-3\\x=7\end{matrix}\right.\)

a.   2x+\(\dfrac{4}{5}\)=0 hoặc 3x-\(\dfrac{1}{2}\)=0

2x=- 4/5 hoặc 3x=1/2

x=-2/5 hoặc x=\(\dfrac{1}{6}\)

b. x-\(\dfrac{2}{5}\)=0 hoặc x+\(\dfrac{4}{7}\)=0

x=2/5 hoặc x=-\(\dfrac{4}{7}\)

d. x(1+5/8-12/16)=1

\(\dfrac{7}{8}\)x=1=> x=8/7

a,x(x-2)+x-2=0

⇔ (x-2)(x+1)=0

⇔ x=2;x=-1

b,x³+x²+x+1=0

⇔ x²(x+1)+x+1=0

⇔ (x+1)(x²+1)=0

⇔ x=-1

\(a,x\left(x+9\right)=0\Rightarrow\left[{}\begin{matrix}x=0\\x=-9\end{matrix}\right.\\ b,\Rightarrow x\left(x^2+4x+4\right)=0\\ \Rightarrow x\left(x+2\right)^2=0\Rightarrow\left[{}\begin{matrix}x=0\\x=-2\end{matrix}\right.\\ c,\Rightarrow\left(x-5-4\right)\left(x-5+4\right)=0\\ \Rightarrow\left(x-9\right)\left(x-1\right)=0\Rightarrow\left[{}\begin{matrix}x=1\\x=9\end{matrix}\right.\\ d,\Rightarrow3\left(x+2\right)-x\left(x+2\right)=0\\ \Rightarrow\left(x+2\right)\left(3-x\right)=0\Rightarrow\left[{}\begin{matrix}x=3\\x=-2\end{matrix}\right.\\ e,\Rightarrow x^3+6x^2+12x+8-x^3-6x^2=4\\ \Rightarrow12x=-4\Rightarrow x=-\dfrac{1}{3}\\ g,\Rightarrow\left(x+2\right)\left(x+3\right)=0\Rightarrow\left[{}\begin{matrix}x=-2\\x=-3\end{matrix}\right.\)

a) pt

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

<=> (x - 5)(x + 4) = 0

<=> x - 5 = 0 hoặc x + 4 = 0

<=> x = 5 hoặc x = -4

b) pt

<=> (2x - 1)(2x - 1 - 2x - 1) = 0

<=> (2x - 1).(-2)=0

<=> 2x - 1 = 0

<=> x = 1/2

c) pt

<=> (x - 1)(x + 1)(x^2 + 4) = 0

<=> x - 1 = 0 hoặc x + 1 = 0 hoặc x^2 + 4 = 0

<=> x = 1 hoặc x = -1

a,x2−52−(x−5)=0<=>(x−5)(x+5)−(x−5)=0<=>(x−5)(x+4)=0=>x=5;x=−4.b,x2−x−6=0<=>x2−3x+2x−6=0<=>x(x−3)+2(x−3)=0<=>(x+2)(x−3)=0=>x=3;x=−2

a. x² - 25 - (x - 5) = 0

<=> x² - 5² - (x - 5) = 0

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

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

<=> (x + 4)(x - 5) = 0

<=> \(\left[{}\begin{matrix}x+4=0\\x-5=0\end{matrix}\right.\)

<=> \(\left[{}\begin{matrix}x=-4\\x=5\end{matrix}\right.\)

b. (2x - 1)² - (4x² - 1) = 0

<=> (2x - 1)² - (2x - 1)(2x + 1) = 0

<=> (2x - 1)(1 - 2x + 1) = 0

<=> (2x - 1)(2 - 2x) = 0

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

c. x²(x² + 4) - x² - 4 = 0

<=> x²(x² + 4) - (x² + 4) = 0

<=> (x² - 1)(x² + 4) = 0

<=> (x - 1)(x + 1)(x² + 4) = 0

<=> \(\left[{}\begin{matrix}x-1=0\\x+1=0\\x^2+4=0\left(VLí\right)\end{matrix}\right.\)

<=> \(\left[{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\)

a: =>x-2=0 và y+3=0

=>x=2 và y=-3

b: =>|x-2|=|x+3|

=>x-2=x+3 hoặc x+3=2-x

=>2x=-1

=>x=-1/2

c: TH1: x<-5/4

Pt sẽ là -x-5/4+3/4-x=1

=>-2x-1/2=1

=>-2x=3/2

=>x=-3/4(loại)

TH2: -5/4<=x<3/4

Pt sẽ là x+5/4+3/4-x=1

=>8/4=1(loại)

TH3: x>=3/4

Pt sẽ là x-3/4+x+5/4=1

=>2x+1/2=1

=>2x=1/2

=>x=1/4(loại)

Em hc bảng xét dáu chx ??

a) Ta có: (x-1)(x-4)>0

\(\Leftrightarrow\left[{}\begin{matrix}x-4>0\\x-1< 0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x>4\\x< 1\end{matrix}\right.\)

b) Ta có: (x-6)(x-7)<0

\(\Leftrightarrow\left\{{}\begin{matrix}x-6>0\\x-7< 0\end{matrix}\right.\Leftrightarrow6< x< 7\)

c) Ta có: \(\left(x-1\right)\left(x-2\right)\le0\)

\(\Leftrightarrow\left\{{}\begin{matrix}x-1\ge0\\x-2\le0\end{matrix}\right.\Leftrightarrow1\le x\le2\)

d) Ta có: \(\left(x-2\right)\left(x-\dfrac{2}{3}\right)\ge0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-2\ge0\\x-\dfrac{2}{3}\le0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x\ge2\\x\le\dfrac{2}{3}\end{matrix}\right.\)

a) Ta có: (x-1)(x-4)>0

⇔[x−4>0x−1<0⇔[x>4x<1⇔[x−4>0x−1<0⇔[x>4x<1

b) Ta có: (x-6)(x-7)<0

⇔{x−6>0x−7<0⇔6<x<7⇔{x−6>0x−7<0⇔6<x<7

c) Ta có: (x−1)(x−2)≤0(x−1)(x−2)≤0

⇔{x−1≥0x−2≤0⇔1≤x≤2⇔{x−1≥0x−2≤0⇔1≤x≤2

d) Ta có: (x−2)(x−23)≥0(x−2)(x−23)≥0

⇔⎡⎣x−2≥0x−23≤0⇔⎡⎣x≥2x≤23