a

\(5\frac{4}{7}:x+=13\)

\(\frac{39}{7}:x=13\)

\(x=\frac{39}{7}:13\)

\(x=\frac{3}{7}\)

\(\frac{4}{7}x=\frac{9}{8}-0,125\)

\(\frac{4}{7}x=1\)

\(x=1:\frac{4}{7}\)

\(x=\frac{7}{4}=1\frac{3}{4}\)

sao bn phũ với mk thế:(( đx ko giải lại còn nói thế

Nó dễ mà :(

A = (19\(\frac58\) : \(\frac{7}{12}\) - 13\(\frac14\): \(\frac72\)) x \(\frac45\) (xem lại đề bài)

B = (9\(\frac{30303}{80808}\) + 7\(\frac{303030}{808080}\)) + 4,03

B = (9\(\frac38\) + 7\(\frac38\)) + 4,03

B =(9 + 7) + (\(\frac38+\frac38\)) + 4,03

B = 16 + 3/4 + 4,03

B = 16 + 0,75 + 4,03

B = 16,75 + 4,03

B = 20,78

Bài 1:

a) Ta có: \(\frac{3}{5}+\frac{4}{15}\)

\(=\frac{9}{15}+\frac{4}{15}\)

\(=\frac{13}{15}\)

b) Ta có: \(\frac{-3}{5}+\frac{5}{7}\)

\(=\frac{-21}{35}+\frac{25}{35}=\frac{4}{35}\)

c) Ta có: \(\frac{5}{6}:\frac{-7}{12}\)

\(=\frac{5}{6}\cdot\frac{-12}{7}=\frac{-60}{42}=\frac{-10}{7}\)

d) Ta có: \(\frac{-21}{24}:\frac{-14}{8}\)

\(=\frac{-7}{8}:\frac{-7}{4}\)

\(=\frac{-7}{8}\cdot\frac{4}{-7}=\frac{4}{8}=\frac{1}{2}\)

e) Ta có: \(\frac{-3}{5}\cdot\frac{5}{7}+\frac{-3}{5}\cdot\frac{3}{7}+\frac{-3}{5}\cdot\frac{6}{7}\)

\(=\frac{-3}{5}\left(\frac{5}{7}+\frac{3}{7}+\frac{6}{7}\right)\)

\(=-\frac{3}{5}\cdot2=\frac{-6}{5}\)

f) Ta có: \(\frac{1}{3}\cdot\frac{4}{5}+\frac{1}{3}\cdot\frac{6}{5}-\frac{4}{3}\)

\(=\frac{1}{3}\cdot\frac{4}{5}+\frac{1}{3}\cdot\frac{6}{5}-\frac{1}{3}\cdot4\)

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

\(=\frac{1}{3}\cdot\left(-2\right)=\frac{-2}{3}\)

g) Ta có: \(\frac{4}{19}\cdot\frac{-3}{7}+\frac{-3}{7}\cdot\frac{5}{19}+\frac{5}{7}\)

\(=\frac{4}{19}\cdot\frac{-3}{7}+\frac{5}{19}\cdot\frac{-3}{7}+\frac{-3}{7}\cdot\frac{5}{-3}\)

\(=-\frac{3}{7}\left(\frac{4}{19}+\frac{5}{19}+\frac{-5}{3}\right)\)

\(=\frac{-3}{7}\cdot\left(\frac{27}{57}+\frac{-95}{57}\right)\)

\(=\frac{-3}{7}\cdot\frac{-68}{57}=\frac{68}{133}\)

h) Ta có: \(\frac{5}{9}\cdot\frac{7}{13}+\frac{5}{9}\cdot\frac{9}{13}-\frac{5}{9}\cdot\frac{3}{13}\)

\(=\frac{5}{9}\left(\frac{7}{13}+\frac{9}{13}-\frac{5}{13}\right)\)

\(=\frac{5}{9}\)

Câu 1a:

\(-\frac36\) = \(\frac{x}{-10}\) = \(\frac{-7}{y}\) = \(\frac{z}{18}\)

-3/6 = x/-10 ⇒ x = -3/6 x (-10) = 5

- 3/6 = - 7/y ⇒ y = -7 : (-3/6) = 14

-3/6 = z/18 ⇒ z = -3/6 x 18 = - 9

Vậy (x; y; z) = (5; 14; -9)

Câu 1b:

\(\frac{x+5}{x-2}=\frac23\)

3.(x+5) = 2.(x -2)

3x + 15 = 2x - 4

3x - 2x = - 15 - 4

x = - 19

Vậy x = - 19

a) \(2x-\frac{2}{3}-7x=\frac{3}{2}-1\\ 2x-7x-\frac{2}{3}=\frac{1}{2}\\ -5x=\frac{1}{2}+\frac{2}{3}\\ -5x=\frac{7}{6}\\ x=\frac{7}{6}:\left(-5\right)\\ x=\frac{-7}{30}\)Vậy \(x=\frac{-7}{30}\)

b) \(\frac{3}{2}x-\frac{2}{5}=\frac{1}{3}x-\frac{1}{4}\\ \frac{3}{2}x-\frac{1}{3}x=\frac{2}{5}-\frac{1}{4}\\ \frac{7}{6}x=\frac{3}{20}\\ x=\frac{3}{20}:\frac{7}{6}\\ x=\frac{9}{70}\)Vậy \(x=\frac{9}{70}\)

c) \(\frac{2}{3}-\frac{5}{3}x=\frac{7}{10}x+\frac{5}{6}\\ \frac{2}{3}-\frac{5}{6}=\frac{7}{10}x+\frac{5}{3}x\\ \frac{-1}{6}=\frac{71}{30}x\\ x=\frac{-1}{6}:\frac{71}{30}\\ x=\frac{-5}{71}\)Vậy \(x=\frac{-5}{71}\)

d) \(2x-\frac{1}{4}=\frac{5}{6}-\frac{1}{2}x\\ 2x+\frac{1}{2}x=\frac{5}{6}+\frac{1}{4}\\ \frac{5}{2}x=\frac{13}{12}\\ x=\frac{13}{12}:\frac{5}{2}\\ x=\frac{13}{30}\)Vậy \(x=\frac{13}{30}\)

e) \(3x-\frac{5}{3}=x-\frac{1}{4}\\ 3x-x=\frac{5}{3}-\frac{1}{4}\\ 2x=\frac{17}{12}\\ x=\frac{17}{12}:2\\ x=\frac{17}{24}\)Vậy \(x=\frac{17}{24}\)

Èo, chăm thế? Chăm hơn cả mik cơ, gần 11 h rồi onl thì thấy bài được bạn HISI làm hết rồi :((