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

=> (2x-1)(x+2)-(x+2)(x+3)=0

=> (x+2)(2x-1-x-3)=0

=> (x+2)(x-4)=0

=> x+2=0=>x=-2

x-4=0=>x=4

Vậy PT có tập nghiệm S=\(\left\{-2;4\right\}\)

số tự nhiên chẵn có 5 chữ số là: 99998

bạn nhé

tk nhé@@@@@@@@@@@@

bye

chắc chưa đang hết câu

thế mình cũng làm được,cách giải

\(\frac{a}{a'}=\frac{b}{b'}=\frac{c}{c'}=\frac{3b}{3b'}=\frac{2c}{2c'}=\frac{a-3b+2c}{a'-3b'+2c'}\) mà\(\frac{a}{a'}=4\Rightarrow\frac{a-3b+2c}{a'-3b'+2c'}\)

Sai. 1/20 = 0,05

số đó là : 1024

This river has been polluted ________ aluminum.

without

within

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with

a)P=\(\frac{x^2+x}{x^2-2x+1}\left(\frac{x+1}{x}-\frac{1}{1-x}+\frac{2-x^2}{x^2-x}\right)\) ĐKXĐ: x \(\ne\) 1;0

P= \(\frac{x\left(x+1\right)}{\left(x-1\right)^2}\left(\frac{\left(x+1\right)\left(x-1\right)}{x\left(x-1\right)}+\frac{x}{x\left(x-1\right)}+\frac{2-x^2}{x\left(x-1\right)}\right)\)

P=\(\frac{x\left(x+1\right)}{\left(x-1\right)^2}\left(\frac{x^2-1+x+2-x^2}{x\left(x-1\right)}\right)\)

P= \(\frac{x\left(x+1\right)}{\left(x-1\right)^2}.\frac{x+1}{x\left(x-1\right)}\)

P= \(\frac{\left(x+1\right)^2}{\left(x-1\right)^3}\)

1. \(\frac{3x-7}{5}=\frac{2x-1}{3}\)

<=> 3(3x-7)=5(2x-1)

<=> 9x-21=10x-5

<=> -21+5=10x-9x

<=> x=-16

2. \(\frac{3x-7}{2}+\frac{2x-1}{3}=-16\)

<=> \(\frac{3\left(3x-7\right)}{6}+\frac{2\left(2x-1\right)}{6}=\frac{-96}{6}\)

=> 9x-21+4x-2=-96

<=> 13x-23=-96

<=> 13x=-73

<=> x=\(\frac{-73}{13}\)

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

<=> \(\frac{15x}{15}-\frac{5\left(x+1\right)}{15}=\frac{3\left(2x+1\right)}{15}\)

=> 15x-5x-5=6x+3

<=> 15x-5x-6x=3+5

<=> 4x=8

<=> x=2

4. \(\frac{7-3x}{12}+\frac{3}{4}=2\left(x-2\right)+\frac{5-\left(5-2x\right)}{6}\)

<=>\(\frac{7-3x}{12}+\frac{9}{12}=\frac{24\left(x-2\right)}{12}+\frac{2\left[5-\left(5-2x\right)\right]}{12}\)

=> 7-3x+9=24x-48+4x

<=> -3x-24x-4x=-48-7

<=> -31x=-55

<=> x= \(\frac{55}{31}\)

5. \(\frac{2x-1}{3}-\frac{5x+2}{7}=x+13\)

<=> \(\frac{7\left(2x-1\right)}{21}-\frac{3\left(5x+2\right)}{21}=\frac{21\left(x+13\right)}{21}\)

=> 14x-7-15x-6=21x+273

<=> 14x-15x-21x=273+7+6

<=> -22x=286

<=> x= -13