Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Bài 1 :
A = 1 - 1/2 + 1/2 - 1/4 + 1/4 - 1/8 + 1/8 - 1/16 + ... + 1/32 - 1/64
A = 1 - 1/64
A = 63/64
\(\frac{1}{2}:\frac{3}{2}:\frac{5}{4}:\frac{6}{5}:\frac{7}{6}:\frac{8}{7}\)
\(=\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{4}{5}\cdot\frac{5}{6}\cdot\frac{6}{7}\cdot\frac{7}{8}\)
\(=\frac{1\cdot\left(2\cdot5\cdot6\cdot7\right)}{8\cdot3\cdot\left(2\cdot5\cdot6\cdot7\right)}\)
\(=\frac{1}{24}\)
\(\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot\frac{4}{5}\cdot\frac{5}{6}\cdot\frac{6}{7}\cdot\frac{7}{8}\cdot\frac{8}{9}\cdot\frac{9}{10}\)
\(=\frac{1\cdot\left(2\cdot3\cdot4\cdot5\cdot6\cdot7\cdot8\cdot9\right)}{\left(2\cdot3\cdot4\cdot5\cdot6\cdot7\cdot8\cdot9\right)\cdot10}\)
\(=\frac{1}{10}\)
\(a.\frac{4}{3}-\frac{3}{2}:X=\frac{1}{6}\)
\(\frac{3}{2}:X=\frac{4}{3}-\frac{1}{6}\)
\(\frac{3}{2}:X=\frac{8}{6}-\frac{1}{6}\)
\(\frac{3}{2}:X=\frac{7}{6}\)
\(X=\frac{3}{2}:\frac{7}{6}\)
\(X=\frac{3}{2}\times\frac{6}{7}\)
\(X=\frac{9}{7}\)
\(b.\left(X+\frac{2}{3}\right):\frac{1}{3}=\frac{41}{3}\)
\(X-\frac{2}{3}=\frac{41}{3}.\frac{1}{3}\)
\(X-\frac{2}{3}=\frac{41}{9}\)
\(X=\frac{41}{9}+\frac{2}{3}\)
\(X=\frac{41}{9}+\frac{6}{9}\)
\(X=\frac{47}{9}\)
\(a,\frac{5}{6}+x\)x \(\frac{3}{4}=3\)
\(x\)x \(\frac{3}{4}=3-\frac{5}{6}\)
\(x\)x \(\frac{3}{4}=\frac{13}{6}\)
\(x=\frac{13}{6}:\frac{3}{4}\)
\(x=\frac{26}{9}\)
b, \(5\frac{1}{6}-x:\frac{3}{4}=\frac{2}{3}\)
\(\frac{31}{6}-x:\frac{3}{4}=\frac{2}{3}\)
\(x:\frac{3}{4}=\frac{31}{6}-\frac{2}{3}\)
\(x:\frac{3}{4}=\frac{9}{2}\)
\(x=\frac{9}{2}\)x \(\frac{3}{4}\)
\(x=\frac{27}{8}\)
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Thank you!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Ta có \(x.a=b\)
\(x=b:a\)
Do đó \(-\frac{3}{5}.x=\frac{5}{6}\)
\(x=\frac{5}{6}:\frac{-3}{5}\)
\(x=-\frac{1}{2}\)
Tương tự
2. \(x=\frac{6}{8}:\frac{2}{4}=\frac{3}{2}\)
Bạn tự làm câu 3
1.\(\frac{-3}{5}\).x=\(\frac{5}{6}\)
x=\(\frac{5}{6}\):\(\frac{-3}{5}\)
x=\(\frac{-25}{18}\)
2.\(\frac{2}{4}\):x=\(\frac{6}{8}\)
\(\frac{1}{2}\):x=\(\frac{3}{4}\)
x=\(\frac{1}{2}\):\(\frac{3}{4}\)
x=\(\frac{2}{3}\)
3.\(\frac{67}{89}\).x=\(\frac{12}{13}\)
x=\(\frac{12}{13}\):\(\frac{67}{89}\)
x=\(\frac{1068}{871}\)
K MIK NHÉ