a) \(\left(3x-1\right)^6=\left(3x-1\right)^4\)

\(\Rightarrow\left[{}\begin{matrix}3x-1=0\\3x-1=1\\3x-1=-1\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{1}{3}\\x=\dfrac{2}{3}\\x=0\end{matrix}\right.\)

b) Áp dụng t/c dtsbn:

\(\dfrac{a+b-c}{c}=\dfrac{a-b+c}{b}=\dfrac{-a+b+c}{a}=\dfrac{a+b+c}{a+b+c}=1\)

\(\Rightarrow\left\{{}\begin{matrix}a+b-c=c\\a-b+c=b\\-a+b+c=a\end{matrix}\right.\)\(\Rightarrow\left\{{}\begin{matrix}a+b=2c\\a+c=2b\\b+c=2a\end{matrix}\right.\)

\(\Rightarrow M=\dfrac{\left(a+b\right)\left(b+c\right)\left(c+a\right)}{abc}=\dfrac{2a.2b.2c}{abc}=8\)

Giúp Mình Với

Mình Đang Cần Gấp

a: \(\Leftrightarrow\left(3x-1\right)^4\cdot\left(3x-2\right)\cdot3x=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{1}{3}\\x=\dfrac{2}{3}\end{matrix}\right.\)

1 went

2 have never been

3 haven't seen

4 saw

5 have they been

6 got

7 have already done

1. I went to the new Mexican restaurant yesterday.

2. I have never been there. Did you like it?

3. I have not seen Ann for a very long time. 

4. Really? I saw her yesterday at the gym.

5. How long have they been married?

6. Only a year. They got married last June. 

7. No, you don't have to. I have already done it.

discovery -> discoveries

such -> so

a -> x

so -> such

lovely a -> a lovely

what -> that

black new -> new black 

What -> That's or such ->x

\(=\dfrac{1}{2}\times\dfrac{2}{3}\times\dfrac{3}{4}\times...\times\dfrac{2008}{2009}\)

\(=\dfrac{1}{2009}\)

=> B

B

B

Ta có: \(\frac{x}{1,75}\)=\(\frac{y}{0,75}\) và x-y = 4

⇒ \(\frac{x}{1,75}\)=\(\frac{y}{0,75}\)=\(\frac{x-y}{1,75-0,75}\)=\(\frac{4}{1}\)=4

⇒\(\frac{x}{1,75}\)=4 ⇔ x = 4 . 1,75 = 7

⇒\(\frac{y}{0,75}\)= 4 ⇔ y = 4 . 0,75 = 3

Vậy x = 7 ; y = 3

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

\(\Leftrightarrow x-\dfrac{1}{5}=\dfrac{2}{5}\Leftrightarrow x=\dfrac{3}{5}\)

pt \(\Leftrightarrow\)\(\left[{}\begin{matrix}x-\dfrac{1}{5}=\dfrac{2}{5}\\x-\dfrac{1}{5}=-\dfrac{2}{5}\end{matrix}\right.\)\(\Leftrightarrow\)\(\left[{}\begin{matrix}x=\dfrac{3}{5}\\x=-\dfrac{1}{5}\end{matrix}\right.\)

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

\(\Rightarrow\left(x-\dfrac{1}{5}\right)^2=\left(\pm\dfrac{2}{5}\right)^5\)

\(\Rightarrow\left[{}\begin{matrix}x-\dfrac{1}{5}=\dfrac{2}{5}\\x-\dfrac{1}{5}=-\dfrac{2}{5}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{2}{5}+\dfrac{1}{5}=\dfrac{3}{5}\\x=-\dfrac{2}{5}+\dfrac{1}{5}=\dfrac{-1}{5}\end{matrix}\right.\)

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

⇒ Yes, I do. Because I can keep fit by doing it.

Yes. Because it brings many benefits for our health

yes.because it's good for health