Bài của mình bị thiếu 1 trường hợp nên bạn tham khảo bài của bạn kia nhé. :<<

\(\left(1-x\right)^2-1\frac{3}{9}=1\frac{4}{9}\)

=> \(\left(1-x\right)^2=1\frac{4}{9}+1\frac{3}{9}=\frac{25}{9}\)

=> \(\left(1-x\right)^2=\left(\frac{5}{3}\right)^2\)

=> \(\orbr{\begin{cases}1-x=\frac{5}{3}\\1-x=-\frac{5}{3}\end{cases}}\)

=> \(\orbr{\begin{cases}x=-\frac{2}{3}\\x=\frac{8}{3}\end{cases}}\)

ĐK : x \(\ne\)0 ; \(x\ne-4\)

Ta có : \(\frac{1}{5}+\frac{1}{45}+\frac{1}{117}+...+\frac{1}{x\left(x+4\right)}=\frac{53}{216}\)

\(\Rightarrow\frac{1}{1.5}+\frac{1}{5.9}+\frac{1}{9.13}+...+\frac{1}{x\left(x+4\right)}=\frac{53}{216}\)

=> \(\frac{1}{4}.\left(\frac{4}{1.5}+\frac{4}{5.9}+\frac{4}{9.13}+...+\frac{4}{x\left(x+4\right)}\right)=\frac{53}{216}\)

=> \(1-\frac{1}{5}+\frac{1}{5}-\frac{1}{9}+\frac{1}{9}-\frac{1}{13}+...+\frac{1}{x}-\frac{1}{x+4}=\frac{53}{216}:\frac{1}{4}\)

=> \(1-\frac{1}{x+4}=\frac{53}{54}\)

=> \(\frac{1}{x+4}=\frac{1}{54}\)

=> x + 4 = 54

=> x = 50 (tm)

Vậy x = 50

Generally, most people in the world all have a hobby. And I have some hobbies, too.  I reading, cooking, and listening to music. I don't think hobbies need hidden but don't share too many people know this. I want to share my hobby with my family and some friends. Some hobbies when I was a baby but some hobbies do a lot and feel good and follow. If you don't have a hobby, you will think life is so terrible so hobby is very important. The hobby is good for us but spends too much time on a hobby is harmful. I think I will try to learn English by listening to some English music. I think I need a computer or a phone and internet for this hobby. In my country, mostly the boy playing soccer and the girl chatting. Hobby helps us confident and happy.

\(a)\frac{5}{6}+\left(\frac{-1}{2}\right)+\frac{3}{4}\)

\(=\frac{1}{3}+\frac{3}{4}\)

\(=\frac{13}{12}\)

\(b)\left(0,75-\frac{1}{3}\right):\frac{7}{15}\)

\(=\left(\frac{3}{4}-\frac{1}{3}\right).\frac{15}{7}\)

\(=\frac{5}{12}.\frac{15}{7}\)

\(=\frac{25}{28}\)

\(c)\frac{7}{12}-\frac{3}{4}.\frac{5}{6}\)

\(=\frac{7}{12}-\frac{5}{8}\)

\(=\frac{-1}{24}\)

\(d)\left(2\frac{1}{3}+1\frac{3}{4}\right).\frac{12}{13}\)

\(=\left(\frac{7}{3}+\frac{7}{4}\right).\frac{12}{13}\)

\(=\frac{49}{12}.\frac{12}{13}\)

\(=\frac{49}{13}\)

a)\(\frac{5}{6}+\frac{-1}{2}+\frac{3}{4}=\frac{10}{12}-\frac{6}{12}+\frac{9}{12}=\frac{10-6+9}{12}=\frac{13}{12}\)

b)\(\left\{0,75-\frac{1}{3}\right\}:\frac{7}{15}=\left\{\frac{3}{4}-\frac{1}{3}\right\}.\frac{15}{7}=\left\{\frac{9}{12}-\frac{4}{12}\right\}.\frac{15}{7}=\frac{5}{12}.\frac{15}{7}=\frac{75}{84}\)

c)\(\frac{7}{12}-\frac{3}{4}.\frac{5}{6}=\frac{7}{12}-\frac{5}{8}=\frac{14}{24}-\frac{15}{24}=\frac{-1}{24}\)

d)\(\left\{2\frac{1}{3}+1\frac{3}{4}\right\}.\frac{12}{13}=\left\{\frac{7}{3}+\frac{7}{4}\right\}.\frac{12}{13}=\left\{\frac{28}{12}+\frac{21}{12}\right\}.\frac{12}{13}=\frac{39}{12}.\frac{12}{13}=3\)

làm ơn giúp mình với.

Vận tốc tàu hỏa là:

 (320+90):41=10

do vụ rơi thiên thạch gây ra sự tuyệt chủng của khủng long
 

Những con khủng long từng một thời tung hoành trên trái đất đã bị hủy diệt bởi một thiên thạch khổng lồ cách đây 65 triệu năm. Đó là kết luận cuối cùng của một ủy ban quốc tế gồm 41 chuyên gia tới từ Mỹ, Mexico, Canada, Nhật Bản và châu Âu.

bạn phải chơi doll thì mới làm dược