Giải:

(1-1/2²).(1-1/3²).(1-1/4²).....(1-1/10²)

=3/2.2 . 8/3.3 . 15/4.4 . ... . 99/10.10

=1.3.2.4.3.5.....9.11/2.2.3.3.4.4.....10.10

=1.2.3.....9/2.3.4.....10 . 3.4.5....11/2.3.4.....10

=1/10.11/2

=11/20

Chúc bạn học tốt!

\(\dfrac{x}{15}\)+\(\dfrac{x}{12}\)=4/1+1/2=9/2

=>x(\(\dfrac{1}{15}\)+\(\dfrac{1}{12}\))=9/2

=>x\(\cdot\)\(\dfrac{3}{20}\)=9/2

=>x=9/2:3/20=30

Vậy x=30

\(\dfrac{x}{15}+\dfrac{x}{12}=\dfrac{9}{2}\Rightarrow\left(\dfrac{1}{15}+\dfrac{1}{12}\right)x=\dfrac{9}{2}\)

\(\Rightarrow\left(\dfrac{12+18}{180}\right)x=\dfrac{9}{2}\Rightarrow\dfrac{30}{180}x=\dfrac{9}{2}\Rightarrow\dfrac{1}{6}x=\dfrac{9}{2}\Rightarrow x=\dfrac{9}{2}.6=27\)

a: \(x+\dfrac{3}{9}=\dfrac{7}{6}\cdot\dfrac{2}{3}\)

=>\(x+\dfrac{1}{3}=\dfrac{14}{18}=\dfrac{7}{9}\)

=>\(x=\dfrac{7}{9}-\dfrac{1}{3}=\dfrac{7}{9}-\dfrac{3}{9}=\dfrac{4}{9}\)

b: \(x-\dfrac{2}{3}=\dfrac{1}{8}:\dfrac{5}{4}\)

=>\(x-\dfrac{2}{3}=\dfrac{1}{8}\cdot\dfrac{4}{5}=\dfrac{1}{10}\)

=>\(x=\dfrac{1}{10}+\dfrac{2}{3}=\dfrac{3+20}{30}=\dfrac{23}{30}\)

TThế giới oi oi oi 

Em bấm vào biểu tượng \(\sum\) trên thanh công cụ và gõ phân số để mn dễ hỗ trợ nhé!

`(x^2+x-6)/(x^2+4x+3):(x^2-10x+25)/(x^2-4x-5)(x ne -1,x ne 5,x ne -3)`

`=((x-2)(x+3))/((x+1)(x+3)):(x-5)^2/((x+1)(x-5))`

`=(x-2)/(x+1):(x-5)/(x+1)`

`=(x-2)/(x-5)`

\(\dfrac{x^2+x-6}{x^2+4x+3}=\dfrac{\left(x+3\right)\left(x-2\right)}{\left(x+3\right)\left(x+1\right)}=\dfrac{x-2}{x+1}\)

\(\dfrac{x^2-10x+25}{x^2-4x-5}=\dfrac{\left(x-5\right)^2}{\left(x-5\right)\left(x+1\right)}=\dfrac{x-5}{x+1}\)

a) Ta có: \(\dfrac{6x^2-8xy}{9xy-12y^2}\)

\(=\dfrac{2x\left(3x-4y\right)}{3y\left(3x-4y\right)}=\dfrac{2x}{3y}\)
b) \(\dfrac{2a^3-18a}{a^4-81}\)

\(=\dfrac{2a\left(a^2-9\right)}{\left(a^2-9\right)\left(a^2+9\right)}=\dfrac{2a}{a^2+9}\)

1. What do you do for fun? 

2. It is a not hobby for her.

3. Why do you like it?

4. When did you start your hobby?

5. Do you intend to continue your hobby in the future?

6. I can't help doing it from time to time.

7. Sarah enjoys collecting cover bag tea.

8. That does not much fun it sound

9. I love doing nothing in my spare time.

10. Do you find collecting seashells interesting?

\(-x-2=\frac{5}{4}\)

\(\Rightarrow-x=\frac{5}{4}+2=\frac{13}{4}\)

\(\Rightarrow x=\frac{-13}{4}\)

\(-x-2=\frac{5}{4}\)

\(-x=\frac{5}{4}+2\)

\(-x=\frac{13}{4}\)

\(x=-\frac{13}{4}\)

-x - 2 = 5/4

=> -x = 5/4 + 2

=> -x = 13/4

=> x = -13/4

\(\left(x-1\right)\left(x+1\right)\left(x+2\right)=0\)

\(TH1:x-1=0\Leftrightarrow x=1\)

\(TH2:x+1=0\Leftrightarrow x=-1\)

\(TH3:x+2=0\Leftrightarrow x=-2\)

nhân đa thức vs đa thức , ko phải tìm x đâu bạn ạ! dù sao cững cảm ơn nh!

3.4²+(5⁷:5⁶)-(2.2⁴)

=3.4²+5^7-6-2⁴⁺¹

=3.4²+5¹-2⁵

=(3.4²)+5-32

=48+5-32

=53-32

=21

để làm gì mà cần thế

3.4²+(5⁷:5⁶)-(2.2⁴)

=3.4²+5^7-6-2⁴⁺¹

=3.4²+5¹-2⁵

=(3.4²)+5-32

=48+5-32

=53-32

=21