a: 2/(x-2)=3/(x+2)

=>3x-6=2x+4

=>x=10

b: (x-2)(x+5)=0

=>x-2=0 hoặc x+5=0

=>x=2 hoặc x=-5

c: 2(x+2)-x=4

=>2x+4-x=4

=>x=0

\(a,\dfrac{2}{x-2}=\dfrac{3}{x+2}\)

\(\Leftrightarrow\dfrac{2}{x-2}-\dfrac{3}{x+2}=0\)

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

\(\Leftrightarrow2x+4-3x+6=0\)

\(\Leftrightarrow-x+10=0\)

\(\Leftrightarrow-x=-10\)

\(\Leftrightarrow x=10\)

\(b,\left(x-2\right)\left(x+5\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\x+5=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-5\end{matrix}\right.\)

\(c,2\left(x+2\right)-x=4\)

\(\Leftrightarrow2x+4-x-4=0\)

\(\Leftrightarrow x=0\)

\(x=\dfrac{3}{4}+\dfrac{1}{5}=\dfrac{15}{20}+\dfrac{4}{20}=\dfrac{19}{20}\)

 x - 1/5 = 3/4

x= 3/4 + 1/5

x = 15/20 + 4/20

x = 19 /20

\(x-\dfrac{1}{5}=\dfrac{3}{4}\)

\(x=\dfrac{3}{4}+\dfrac{1}{5}\)

\(x=\dfrac{19}{20}\)

⇒4y+6=6+5

⇒4y=5x

⇒y=\(\dfrac{5x}{4}\)=1,25x

⇒x=\(\dfrac{4y}{5}\)=0.8y

\(a.\left(-3\right).\left(-2\right).\left(-5\right).4=6.\left(-5\right).4=\left(-30\right).4=-120\)

\(\left(-3\right)\cdot\left(-2\right)\cdot\left(-5\right)\cdot4=6\cdot\left(-5\right)\cdot4=\left(-30\right)\cdot4=-120\)

\(\left(-3\right)\cdot\left(-2\right)\cdot\left(-5\right)\cdot4=6\cdot\left(-20\right)=-120\)

gíup mình nha 

a, \(\frac{2x}{5}+\frac{3-2x}{3}\ge\frac{3x+2}{2}\)

\(\Leftrightarrow\frac{12x}{30}+\frac{30-20x}{30}\ge\frac{45x+30}{30}\)

\(\Leftrightarrow12x+30-20x\ge45x+30\)

\(\Leftrightarrow-8x+30\ge45x+30\Leftrightarrow-8x-45x\ge0\)

\(\Leftrightarrow-53x\ge0\Leftrightarrow x\le0\)

Vậy tập nghiệm của BFT là S = { x | x =< 0 } 

b, \(\frac{x}{2}+\frac{3-2x}{5}\ge\frac{3x-5}{6}\)

\(\Leftrightarrow\frac{15x}{30}+\frac{18-12x}{30}\ge\frac{15x-25}{30}\)

\(\Leftrightarrow3x+18\ge15x-25\Leftrightarrow43\ge12x\Leftrightarrow x\le\frac{43}{12}\)

Vậy tập nghiệm của BFT là S = { x | x =< 43/12 } 

Ta có: \(a+b=5\Rightarrow a=5-b\)

Thay \(a=5-b\) vào \(2a-b=4\) ta có:

\(2\cdot\left(5-b\right)-b\)

\(\Rightarrow10-2b-b=4\)

\(\Rightarrow10-3b=4\)

\(\Rightarrow3b=10-4\)

\(\Rightarrow3b=6\)

\(\Rightarrow b=\dfrac{6}{3}=2\)

Lúc này ta tìm được \(a\):

\(a=5-b=5-2=3\)

Vậy: \(a=3,b=2\)

a) \(\dfrac{2x+3}{24}=\dfrac{3x-1}{32}\)

\(\Rightarrow32\left(2x+3\right)=24\left(3x-1\right)\)

\(\Rightarrow64x+96=72x-24\)

\(\Rightarrow8x=120\Rightarrow x=15\)

b) \(\dfrac{13x-2}{2x+5}=\dfrac{76}{17}\)

\(\Rightarrow17\left(13x-2\right)=76\left(2x+5\right)\)

\(\Rightarrow221x-34=152x+380\)

\(\Rightarrow69x=414\Rightarrow x=6\)

\(\frac{x+5}{4}-\frac{2x-3}{3}=\frac{6x-1}{8}+\frac{2x-1}{12}\)

\(\Leftrightarrow\frac{6\left(x+5\right)}{24}-\frac{8\left(2x-3\right)}{24}=\frac{3\left(6x-1\right)}{24}+\frac{2\left(2x-1\right)}{24}\)

\(\Leftrightarrow6x+30-16x+24=18x-3+4x-2\)

\(\Leftrightarrow6x-16x-18x-4x=-2-3-24-30\)

\(\Leftrightarrow-32x=-59\)

\(\Leftrightarrow x=\frac{59}{32}\)