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\(\frac{2}{x-1}+\frac{5}{x+2}=\frac{13}{x^2+x-2}.\)
\(\Leftrightarrow\frac{2\left(x+2\right)}{\left(x-1\right)\left(x+2\right)}+\frac{5\left(x-1\right)}{\left(x+2\right)\left(x-1\right)}=\frac{13}{x^2+x-2}\)
\(\Leftrightarrow\frac{2x+4}{x^2+x-2}+\frac{5x-5}{x^2+x-2}=\frac{13}{x^2+x-2}\)
\(\Leftrightarrow\frac{7x-1}{x^2+x-2}=\frac{13}{x^2+x-2}\)
\(\Leftrightarrow7x-1=13\)
\(\Leftrightarrow7x=14\)
\(\Leftrightarrow x=2\)
\(\frac{\left(x-2\right)^2}{12}-\frac{\left(x+1\right)^2}{21}=\frac{\left(x-4\right)\left(x-6\right)}{28}\)
\(\Leftrightarrow\frac{7\left(x-2\right)^2}{84}-\frac{4\left(x+1\right)^2}{84}=\frac{3\left(x-4\right)\left(x-6\right)}{84}\)
\(\Leftrightarrow7\left(x-2\right)^2-4\left(x+1\right)^2=3\left(x-4\right)\left(x-6\right)\)
\(\Leftrightarrow7\left(x^2-4x+4\right)-4\left(x^2+2x+1\right)=3\left(x^2-10x+24\right)\)
\(\Leftrightarrow7x^2-28x+28-4x^2-8x-4=3x^2-30x+72\)
\(\Leftrightarrow7x^2-4x^2-3x^2-28x-8x+30+28-4-72=0\)
\(\Leftrightarrow-6x-48=0\)
\(\Leftrightarrow-6x=48\)
\(\Leftrightarrow x=-8\)
Vậy tập nghiệm của PT là : \(S=\left\{-8\right\}\)
Chúc bạn học tốt !!!
\(\(\frac{\left(x-2\right)^2}{12}-\frac{\left(x+1\right)^2}{21}=\frac{\left(x-4\right)\left(x-6\right)}{28}\)\)
\(\Leftrightarrow\frac{7\left(x^2-4x+4\right)}{84}-\frac{4\left(x^2+2x+1\right)}{84}=\frac{3\left(x^2-6x-4x+24\right)}{84}\)
\(\Rightarrow7x^2-28x+28-4x^2-8x-4=3x^2-30x+\frac{72}{ }\)
\(\Leftrightarrow3x^2-36x+24=3x^2-30x+72\)
\(\Leftrightarrow-6x=48\Leftrightarrow x=-8\)
- Cố gắng tham khảo vì giờ muộn rồi , nếu post sớm thì mình có thể giúp !
Tet, also known as Lunar new year festival, is the biggest traditional festival in Viet Nam. Tet is usually from the end of January to early February. Before Tet, Vietnamese prepare many things for the three main days. They clean their house and decorate with flowers such as kumquat tree or peach blossom. A huge amount of food will be bought before Tet for making traditional dishes. Banh Chung, Banh Tet, Gio cha, Xoi and Mut, …and candies are the foods that must have on Tet holidays. During Tet, people visit their relatives’ homes and give wishes. However, the Vietnamese believe that the first visitor a family receives in the year determines their fortune for the entire year, people never enter any house on the first day without being invited first. Another custom is giving lucky money, which is put into a red envelope as a symbol of luck and wish for a new age. Traditionally, elders will give lucky money to children and the oldest people in the family. However, nowadays, people can give it to anyone including friends, parents, neighbors,… Besides, Vietnamese usually go to pagodas or temples to pray for health, wealth, success,… To Vietnamese, Tet is the happiest time of all year around, members in a family can gather together, which is a meaningful messages of Lunar New year festival. All in all, Tet is all about back to origins, be good to others, enjoy the precious moment, and wish for the best to come.
Tet, also known as Lunar new year festival, is the biggest traditional festival in Viet Nam. Tet is usually from the end of January to early February. Before Tet, Vietnamese prepare many things for the three maindays. They clean their house and decorate with flowers such as kumquat tree or peach blossom. A huge amount of food will be bought before Tet for making traditional dishes. Banh Chung, Banh Tet, Gio cha, Xoi and Mut, …and candies are the foods that must have on Tet holidays. During Tet, people visit their relatives’ homes and give wishes. However, the Vietnamese believe that the first visitor a family receives in the year determines their fortune for the entire year, people never enter any house on the first day without being invited first. Another custom is giving lucky money, which is put into a red envelope as a symbol of luck and wish for a new age. Traditionally, elders will give lucky money to children and the oldest people in the family. However, nowadays, people can give it to anyone including friends, parents, neighbors,… Besides, Vietnamese usually go to pagodas or temples to pray for health, wealth, success,… To Vietnamese, Tet is the happiest time of all year around, members in a family can gather together, which is a meaningful messages of Lunar New year festival. All in all, Tet is all about back to origins, be good to others, enjoy the precious moment, and wish for the best to come
0. I ( meet)……met……..an interesting man when I ( be)……was………on holiday in Italy.
1. I (have/ walk)…………Had to walk…….. home last night because my bike (break)……had broken………. down.
2. What you (have/ do)…………did-do……. to help your mother last Tet holiday?
3. What you (have/ prepare)……did-prepare…….. for your last birthday party?
4. Nam used ……to smoke………(smoke) but now he (not/ smoke)……doesn't smoke………… any more.
5. What Nam (do)………has-been doing…. since early morning? He (do)…………has been doing……. his homework.
6. John (work)………has worked……….. for a car export company for 10 years.
7. My sister (be)………has been……a teacher of English for 12 years so far.
8. My son (be)……has been… in Hong Kong since he (graduate)……graduated……. his university. He (be) …has been……there for ten months.
9. Tom (not/ write)…………hasn't written……. home for a year
10. John and Mary (be)………have been……….. married for over twenty years.
11. David (leave)……left……… New York last month. I (not/ meet)……haven't seen……….. him since then.
12. The car looks very clean.…Have…..You (clean)…clean…. it?
13. Carlos (come)……came……. to London last Christmas. When he (arrive)…arrive……….., he (go)…went….. to stay with some friends. He (be)……has been……. in London for a month.
14. Barbara (be)……was… a writer. She (write)……has written…. a lot of books. She (write)……wrote…… her first book fifteen years ago.
15. We already ( finish) ………have-finished…….our work.
16. This is the first time I (meet)………have met………this man.
17. How long you ( know)……have-known…………..Mrs. Chi?- I ( know)………have known…….her for five years.
18. We ( not/ see)………haven't seen………her since we ( be)……were………….on holiday in Ha long bay.
Như Quỳnh Quách bạn hỏi lộn sang group Anh rồi bn
Bạn hỏi lộn rồi nhưng mk sẽ giúp :))
a, mx + 2 = 0
\(\Rightarrow\) m \(\ne\) 0 để mx + 2 = 0 là phương trình bậc nhất
b, (2 - m)x + 2m = 0
\(\Leftrightarrow\) 2x - mx + 2m = 0
\(\Leftrightarrow\) 2x - m(x - 2) = 0
\(\Rightarrow\) m \(\ne\) 0 để (2 - m)x + 2m = 0 là phương trình bậc nhất
c, mx2 - x + 2m = 0
\(\Leftrightarrow\) m(x2 + 2) - x = 0
\(\Rightarrow\) m \(\ne\) 0 để mx2 - x + 2m = 0 là phương trình bậc nhất
d, (m - 1)x2 + mx - 8 = 0
\(\Leftrightarrow\) mx2 - x2 + mx - 8 = 0
\(\Leftrightarrow\) mx(x + 1) - x2 - 8 = 0
\(\Rightarrow\) m \(\ne\) 0 để (m - 1)x2 + mx - 8 = 0 là phương trình bậc nhất
Mk ko bt đúng ko nữa, dạng này mới làm lần đầu, có gì bạn thông cảm giúp mk nha
Chúc bạn học tốt!