Giải giúp mình 3 bài dưới dây với!
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
NH
1
PP
1
8 tháng 12 2021
\(ĐK:x\ne\dfrac{1}{2};x\ne1;x\ne\dfrac{3}{2};x\ne2;x\ne\dfrac{5}{2}\\ PT\Leftrightarrow\dfrac{1}{\left(2x-1\right)\left(x-1\right)}+\dfrac{1}{\left(x-1\right)\left(3x-2\right)}+\dfrac{1}{\left(3x-2\right)\left(x-2\right)}+\dfrac{1}{\left(x-2\right)\left(5x-2\right)}=\dfrac{4}{21}\\ \Leftrightarrow2\left[\dfrac{\dfrac{1}{2}}{\left(x-\dfrac{1}{2}\right)\left(x-1\right)}+\dfrac{\dfrac{1}{2}}{\left(x-1\right)\left(x-\dfrac{3}{2}\right)}+\dfrac{\dfrac{1}{2}}{\left(x-\dfrac{3}{2}\right)\left(x-2\right)}+\dfrac{\dfrac{1}{2}}{\left(x-2\right)\left(x-\dfrac{5}{2}\right)}\right]=\dfrac{4}{21}\)
\(\Leftrightarrow\dfrac{1}{x-1}-\dfrac{1}{x-\dfrac{1}{2}}+\dfrac{1}{x-\dfrac{3}{2}}-\dfrac{1}{x-1}+\dfrac{1}{x-2}-\dfrac{1}{x-\dfrac{3}{2}}+\dfrac{1}{x-\dfrac{5}{2}}-\dfrac{1}{x-2}=\dfrac{2}{21}\\ \Leftrightarrow\dfrac{1}{x-1}-\dfrac{1}{x-\dfrac{5}{2}}=\dfrac{2}{21}\\ \Leftrightarrow\dfrac{x-\dfrac{5}{2}-x+1}{\left(x-1\right)\left(x-\dfrac{5}{2}\right)}=\dfrac{2}{21}\\ \Leftrightarrow\dfrac{-\dfrac{3}{2}}{x^2-\dfrac{7}{2}x+\dfrac{5}{2}}=\dfrac{2}{21}\\ \Leftrightarrow x^2-\dfrac{7}{2}x+\dfrac{5}{2}=-\dfrac{63}{4}\\ \Leftrightarrow4x^2-14x+10=-63\\ \Leftrightarrow4x^2-14x+73=0\\ \Leftrightarrow x\in\varnothing\)
H
14 tháng 1 2022
1. have waited
2. has written
3. has studied
4. has finished
5 haven't done
6. We don't go to school on Saturdays
7. They usually hold a party on New Year's Eve
8. I have seen this film already
9. Last night she came home between 10.30 and 11 o'clock
10. We are going to see the movie Dream City at 7.00 this evening
TP
14 tháng 1 2022
1 have waited
2 has written
3 has studied
4 has finished
5 haven't done
6 We don't go to school on Saturdays.
7 They usually hold a party in New Year's Eve.
8 I've seen this film already.
9 Last night, she came home between 10.30 and 11 o'clock.
10 We are going to see the movie Dream City at 7.00 this evening.
NH
2
H
26 tháng 12 2022
Giải :
\(\dfrac{x+11}{89}+\dfrac{x+13}{87}-\dfrac{x+15}{85}-\dfrac{x+17}{83}=0\\ =>\left(\dfrac{x+11}{89}+1\right)+\left(\dfrac{x+13}{87}+1\right)-\left(\dfrac{x+15}{85}+1\right)-\left(\dfrac{x+17}{83}+1\right)=0\\ =>\left(\dfrac{x+11+89}{89}\right)+\dfrac{x+13+87}{87}-\dfrac{x+15+85}{85}-\dfrac{x+17+83}{83}=0\\ =>\dfrac{x+100}{89}+\dfrac{x+100}{87}-\dfrac{x+100}{85}-\dfrac{x+100}{83}=0\\ =>\left(x+100\right)\left(\dfrac{1}{89}+\dfrac{1}{87}-\dfrac{1}{85}-\dfrac{1}{83}\right)=0\\ =>\left[{}\begin{matrix}x+100=0\\\dfrac{1}{89}+\dfrac{1}{87}-\dfrac{1}{85}-\dfrac{1}{83}=0\left(voli\right)\end{matrix}\right.=>x=-100\)
NH
1
NH
2
H
26 tháng 12 2022
\(2x=3y\\ =>\dfrac{x}{3}=\dfrac{y}{2}\\ 4y=5z\\ =>\dfrac{y}{5}=\dfrac{z}{4}\\ \dfrac{x}{3}=\dfrac{y}{2}\\ =>\dfrac{x}{3.5}=\dfrac{y}{2.5}\\ =>\dfrac{x}{15}=\dfrac{y}{10}\\ \dfrac{y}{5}=\dfrac{z}{4}\\ =>\dfrac{y}{5.2}=\dfrac{z}{4.2}\\ =>\dfrac{y}{10}=\dfrac{z}{8}\\ =>\dfrac{x}{15}=\dfrac{y}{10}=\dfrac{z}{8}\)
Áp dụng tính chất dãy tỉ số bằng nhau
\(\dfrac{x}{15}=\dfrac{y}{10}=\dfrac{z}{8}=\dfrac{x+y+z}{15+10+8}=\dfrac{11}{33}=\dfrac{1}{3}\\ =>\left\{{}\begin{matrix}x=\dfrac{1}{3}.15=5\\y=\dfrac{1}{3}.10=\dfrac{10}{3}\\z=\dfrac{1}{3}.8=\dfrac{8}{3}\end{matrix}\right.\)
NH
2
H
26 tháng 12 2022
Giải
\(\dfrac{x}{3}=\dfrac{y}{4}\\ \Leftrightarrow\dfrac{x}{3.3}=\dfrac{y}{4.3}\\\Leftrightarrow\dfrac{x}{9}=\dfrac{y}{12}\\ \dfrac{y}{3}=\dfrac{z}{5}\\ \Leftrightarrow \dfrac{y}{3.4}=\dfrac{z}{5.4}\\ \Leftrightarrow\dfrac{y}{12}=\dfrac{z}{20}\\ =>\dfrac{x}{9}=\dfrac{y}{12}=\dfrac{z}{20}\)
Áp dụng tính chất dãy tỉ số bằng nhau
\(\dfrac{x}{9}=\dfrac{y}{12}=\dfrac{z}{20}=\dfrac{2x+3x+z}{2.9+3.12+20}=\dfrac{6}{74}=\dfrac{3}{37}\\ \Rightarrow\left\{{}\begin{matrix}x=\dfrac{3}{37}\times9=\dfrac{27}{37}\\y=\dfrac{3}{37}\times12=\dfrac{36}{37}\\z=\dfrac{3}{37}\times20=\dfrac{60}{37}\end{matrix}\right.\)
NH
2
NH
2
H
26 tháng 12 2022
\(a,\dfrac{3^{10}.11+9^5.5}{27^3.2^4}.x=-9\\ =>\dfrac{3^{10}.11+\left(3^2\right)^5.5}{\left(3^3\right)^3.2^4}.x=-9\\ =>\dfrac{3^{10}.\left(11+5\right)}{3^9.2^4}.x=-9\\ =>\dfrac{3^{10}.16}{3^9.2^4}.x=-9\\ =>\dfrac{3^{10}.2^4}{3^9.2^4}.x=-9\\ =>3^1.x=-9\\ =>x=-9:3\\ =>x=-3\)
ai vào đây xem bài viết giúp mình với, mình sẽ T.I.C.K :https://olm.vn/bai-viet/my-greatest-victory-198932 CẢM ƠN NHIỀU Ạ! VÀ NẾU ĐƯỢC CÁC BẠN HÃY VOTE BÀI VIẾT GIÚP MÌNH