Tính:
\(2\dfrac{6}{7}[(\dfrac{-7}{5}-\dfrac{3}{2}:\dfrac{-5}{-4})+(\dfrac{3}{2})^2]\)
\(\dfrac{\dfrac{5}{3}-\dfrac{5}{7}+\dfrac{5}{9}}{\dfrac{10}{3}+\dfrac{10}{7}+\dfrac{10}{5}}\)
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ĐKXĐ: \(x+3\ne0\Leftrightarrow x\ne-3\)
\(\dfrac{x+3}{-4}=\dfrac{-9}{x+3}\\ \Leftrightarrow\left(x+3\right)\left(x+3\right)=\left(-9\right).\left(-4\right)\\ \Leftrightarrow\left(x+3\right)^2=6^2\\ \Rightarrow\left[{}\begin{matrix}x+3=6\\x+3=-6\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=3\left(tm\right)\\x=-9\left(tm\right)\end{matrix}\right.\)
Vậy ...
\(\dfrac{x+3}{-4}=\dfrac{-9}{x+3}\)
\(\left(x+3\right)\left(x+3\right)=\left(-9\right)\cdot\left(-4\right)\)
\(\left(x+3\right)^2=36\)
\(\left(x+3\right)^2=6^2\)
\(x+3=6\)
\(x=3\)
-5/14 - 2/14 + 1/8 + 1/8=-1/4
-5/22 - 1 + 3/2 - 6/22=0
-1/2 + 1/4 + 2/8 - 11/77=-1/7
2/5 + 5/4 + (-2/5+5/4)-5/2=0
mình trả lời thế có đúng không nhỉ? 🤔
- \(\dfrac{5}{14}\) - \(\dfrac{2}{14}\) + \(\dfrac{1}{8}\) + \(\dfrac{1}{8}\)
= -(\(\dfrac{5}{14}\) + \(\dfrac{2}{14}\)) + (\(\dfrac{1}{8}\) + \(\dfrac{1}{8}\))
= - \(\dfrac{7}{14}\) + \(\dfrac{2}{8}\)
= - \(\dfrac{1}{2}\) + \(\dfrac{1}{4}\)
= - \(\dfrac{1}{4}\)
Bài 1:
a)
\(\dfrac{1}{-5}=\dfrac{1:-1}{-5:-1}=\dfrac{-1}{5}\)
\(\dfrac{-3}{-15}=\dfrac{-3:-3}{-15:-3}=\dfrac{1}{5}\)
Vì \(-1< 1\) nên\(\dfrac{-1}{5}< \dfrac{1}{5}\)
Vậy \(\dfrac{1}{-5}< \dfrac{-3}{-15}\)
b)
\(\dfrac{25}{-10}=\dfrac{25:-5}{-10:-5}=\dfrac{-5}{2}\)
\(\dfrac{15}{-2}=\dfrac{15:-1}{-2:-1}=\dfrac{-15}{2}\)
Vì \(-5>-15\) nên\(\dfrac{-5}{2}>\dfrac{-15}{2}\)
Vậy \(\dfrac{25}{-10}>\dfrac{15}{-2}\)
Bài 2:
a)
\(\dfrac{300}{540}=\dfrac{300:60}{540:60}=\dfrac{5}{9}\)
b)
\(\dfrac{-38}{95}=\dfrac{-38:19}{95:19}=\dfrac{-2}{5}\)
c)
\(\dfrac{-68}{-85}=\dfrac{-68:-17}{-85:-17}=\dfrac{4}{5}\)
Bài 3:
a)
\(\dfrac{x}{3}=-\dfrac{4}{6}\)
\(\dfrac{x}{6}=-\dfrac{4}{6}\)
\(x=-4\)
b) \(x-\dfrac{1}{3}=\dfrac{8}{6}\)
\(x=\dfrac{8}{6}+\dfrac{1}{3}\)
\(x=\dfrac{5}{3}\)
c) \(\dfrac{x}{9}=\dfrac{4}{x}\)
\(x^2=36\)
\(x=6\)
d) mình có giải câu hỏi trước rồi nhé
Sửa câu c)
\(x^2=36\)
\(\left[{}\begin{matrix}x=6\\x=-6\end{matrix}\right.\)
ĐKXĐ: \(\left\{{}\begin{matrix}x-5\ne0\\x+2\ne0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x\ne5\\x\ne-2\end{matrix}\right.\)
\(\dfrac{3}{x-5}=\dfrac{-4}{x+2}\\ \Leftrightarrow3\left(x+2\right)=-4\left(x-5\right)\\ \Leftrightarrow3x+6=-4x+20\\ \Leftrightarrow7x=14\\ \Leftrightarrow x=2\left(tm\right)\)
Vậy x = 2
1.What/Which are you watching?
2.Which/Who character do you prefer.Snow White or her stepmother?
3.What/Which color do you like?
4.How/What are you doing tonight?
5.Where/When is the book exhibition?-It's in Ngoc Khanh Street.
6.How long/How often does this film last?
7.What/How does she go to work every morning?
8.Why/What don't you like watching horror films?
9.How much/How many times have you seen''Tom and Jerry''?
10.What time/When did you graduate from your primary school?-Last Friday.
1.He watches TV three times a week.
How often does he watch TV?
2.We play volleyball in the playground.
Where do you play volleyball?
3.Chris Evans is my brother's favourite actor.
Who is your brother's favorite actor?
4.I spend two hours watching movies every weekend.
How much time do you spend watching movies every weekend?
5.She likes watching the news because it's very informative.
Why does she like watching the news?
1. How often does he watch TV?
2. Where do we play volleyball?
3. Who is your brother's favourite actor?
4. How long do you spend watching movies every weekend?
5. Why does she like watching the news?
6. When is the sports programme is on?
7. What do they like to watch the best?
8. How often do your grandchildren watch the Wildlife programme?
9. What do you often do in your free time?
10. How does Minh prefer to get information?
1. The VTV programmes attract millions of viewers.
2. The weatherman is describing the weather for this weekend.
3. Quyen Linh is not only a famous actor but also a good MC of game shows.
4. Hoai Anh is one of the most well-known newsreaders on VTV3.
5. The schedule of VTV 1 and VTV 3 are filled with many interesting Vietnamese films.