lm bài 4 thôi nha
bài cuối thôi giải pt nha mng đừng lm tắt tại em khó hỉu
ĐKXĐ: \(x\ge\dfrac{1}{2}\)
\(\Leftrightarrow2x-2\sqrt{2x^2+5x-3}=1+x\left(\sqrt{2x-1}-2\sqrt{x+3}\right)\)
\(\Leftrightarrow2x-1-2\sqrt{\left(2x-1\right)\left(x+3\right)}-x\left(\sqrt{2x-1}-2\sqrt{x+3}\right)=0\)
\(\Leftrightarrow\sqrt{2x-1}\left(\sqrt{2x-1}-2\sqrt{x+3}\right)-x\left(\sqrt{2x-1}-2\sqrt{x+3}\right)=0\)
\(\Leftrightarrow\left(\sqrt{2x-1}-x\right)\left(\sqrt{2x-1}-2\sqrt{x+3}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\sqrt{2x-1}=x\left(x\ge0\right)\\\sqrt{2x-1}=2\sqrt{x+3}\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}2x-1=x^2\\2x-1=4\left(x+3\right)\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=1\\x=-\dfrac{13}{2}\left(loại\right)\end{matrix}\right.\)
có ai bt làm bài này không giúp mk vs mk đg cần rất rất mong các bn giúp cho( lm chắc bài 3 thôi nha)
\(3,\\ a,\dfrac{\left(1+\sqrt{x}\right)^2-4\sqrt{x}}{1-\sqrt{x}}\\ =\dfrac{\sqrt{x}-2\sqrt{x}+1}{1-\sqrt{x}}=\dfrac{\left(1-\sqrt{x}\right)^2}{1-\sqrt{x}}=1-\sqrt{x}=1-\sqrt{2}\)
\(b,\dfrac{\left(\sqrt{x}-\sqrt{y}\right)^2+4\sqrt{xy}}{1+\sqrt{xy}}\\ =\dfrac{x+2\sqrt{xy}+y}{1+\sqrt{xy}}=\dfrac{\left(\sqrt{x}+\sqrt{y}\right)^2}{1+\sqrt{xy}}\\ =\dfrac{\left(\sqrt{2}+\sqrt{3}\right)^2}{1+\sqrt{6}}=\dfrac{5+2\sqrt{6}}{1+\sqrt{6}}\\ =\dfrac{\left(5+2\sqrt{6}\right)\left(\sqrt{6}-1\right)}{5}\\ =\dfrac{3\sqrt{6}+7}{5}\)
m.n giúp mk lm đề này vs đc ko, bài 2b và d, bài 3b và c thôi cx đc THANK YOU VERY MUCH, cảm ơn m.n trc nha
Bài 2
b)\(\overrightarrow{AN}=\dfrac{1}{2}\left(\overrightarrow{AB}+\overrightarrow{AC}\right)\)
\(\overrightarrow{AK}=\dfrac{1}{2}\left(\overrightarrow{AB}+\overrightarrow{AN}\right)=\dfrac{1}{2}\left(\overrightarrow{AB}+\dfrac{1}{2}\overrightarrow{AB}+\dfrac{1}{2}\overrightarrow{AC}\right)=\dfrac{3}{4}\overrightarrow{AB}+\dfrac{1}{4}\overrightarrow{AC}\)
d)\(S_{ABC}=24\Leftrightarrow\dfrac{1}{2}AN.BC=24\Leftrightarrow AN=6\left(cm\right)\)
\(\left|\overrightarrow{AB}+\overrightarrow{AC}\right|=\left|2.\dfrac{1}{2}\left(\overrightarrow{AB}+\overrightarrow{AC}\right)\right|=\left|2\overrightarrow{AN}\right|=2.AN=12\left(cm\right)\)
Bài 3:
b)\(\overrightarrow{BG}=\overrightarrow{BC}+\overrightarrow{CG}=\overrightarrow{BC}+\dfrac{3}{4}\overrightarrow{CA}=\overrightarrow{BC}+\dfrac{3}{4}\left(\overrightarrow{BA}-\overrightarrow{BC}\right)=\dfrac{1}{4}\overrightarrow{BC}+\dfrac{3}{4}\overrightarrow{BA}=\dfrac{1}{4}\overrightarrow{v}+\dfrac{3}{4}\overrightarrow{u}\)
c)Nhìn hình thấy ko thẳng nên đề sai
ko cần lm bài 1 đâu lm bài 2 thôi ạ
Part 1
1.girls
2.are
3.reading
4.boy
5.she's
Part 2
2. No, they aren't. Some girls are making puppets
3. They are red, blue and yellow
4. The girl is reading a text
5. The teacher is in the office
6. Yes, she is reading a book
6.No, they aren't
7.They are painting red, blue and yellow.
8.The girl is reading a text.
9.Our teacher is in the office.
10.Yes, she is.
Câu 9. M là trung điểm EF các bồ nhé ! Lm hộ mik câu 8,9 thôi nha. Lm đc baì naò thì lm thôi nhoa.thanks mấy bồ!
có ai bt giải bài này k giúp mk vs mk đg cần rất rất gấp mong các bn giúp cho( lm VD1 vs VD2 thôi nha)
lm VD1 thôi nha
\(a,5\sqrt{25a^2}-25a\left(a< 0\right)=5\cdot\left|5a\right|-25a=-25a-25a=50a\\ b,\sqrt{49a^2}+3a\left(a>0\right)=\left|7a\right|+3a=10a\\ c,\sqrt{64a^2}-8a\left(a\in R\right)=\left|8a\right|-8a=\left[{}\begin{matrix}0,\forall a\ge0\\-16a,\forall a< 0\end{matrix}\right.\\ d,\sqrt{9a^6}-6a^3=\left|3a^3\right|-6a^3=\left[{}\begin{matrix}-3a^3,\forall a\ge0\\-9a^3,\forall a< 0\end{matrix}\right.\)
nhầm lm cái này thôi nha
Lm bài 1 thôi ẹ
1 Those trees are watered by me everyday
2 Many friends were invited to his birthday party by Jack last week
3 Tea is being made in the kitchen by my dad
4 A lot of water should be drunk by us everyday
5 The painting has just been finished by Jane
6 A serious accident was caused in this street by some young boys last night
7 More doctors and nurses will be sent to the northern area by many hospitals next ......
8 Some rules weren't obeyed at school by John and Jack
9 Was your bike stolen by Jackson
10 Vegetables won't be grown by Mr Bill next winter
11 This factory wasn't built by the German during the Second World War
12 This house and these cars are going to be painted for Christmas
13 THe cats had been fed before she went to the cinema
13 Moon cakes were being made by us at this time last week
14 His work had been finished by Jack before 8 am
lm bài 1 thôi ạ
`#3107.101107`
a)
\(\dfrac{-22}{25}+\left(\dfrac{3}{7}-0,12\right)\\ =\dfrac{-22}{25}+\dfrac{3}{7}-0,12\\ =-\dfrac{79}{175}-0,12\\ =-\dfrac{4}{7}\)
b)
\(\dfrac{3}{8}-\left(1,2-\dfrac{5}{8}\right)\\ =\dfrac{3}{8}-1,2+\dfrac{5}{8}\\ =\dfrac{8}{8}-1,2\\ =1-1,2\\ =-0,2\)
c)
\(\dfrac{4}{15}-\left(2,9-\dfrac{11}{15}\right)\\ =\dfrac{4}{15}-2,9+\dfrac{11}{15}\\=\dfrac{15}{15}-2,9\\ =1-2,9\\ =-1,9\)
d)
\(\dfrac{17}{11}-\left(\dfrac{6}{5}-\dfrac{16}{11}\right)+\dfrac{26}{5}\\ =\dfrac{17}{11}-\dfrac{6}{5}+\dfrac{16}{11}+\dfrac{26}{5}\\ =\left(\dfrac{17}{11}+\dfrac{16}{11}\right)+\left(-\dfrac{6}{5}+\dfrac{26}{5}\right)\\ =\dfrac{33}{11}+\dfrac{20}{5}\\ =3+4\\ =7\)
e)
\(\dfrac{39}{5}+\left(\dfrac{9}{4}-\dfrac{9}{5}\right)-\left(\dfrac{5}{4}+\dfrac{6}{7}\right)\\ =\dfrac{39}{5}+\dfrac{9}{4}-\dfrac{9}{5}-\dfrac{5}{4}-\dfrac{6}{7}\\ =\left(\dfrac{39}{5}-\dfrac{9}{5}\right)+\left(\dfrac{9}{4}-\dfrac{5}{4}\right)-\dfrac{6}{7}\\ =\dfrac{30}{5}+\dfrac{4}{4}-\dfrac{6}{7}\\ =6+1-\dfrac{6}{7}\\=\dfrac{43}{7}\)