does

goes

Nguyễn Minh Dương

Bạn xem lại câu a nhé.

a) 6 . x - 15 = 15

6 . x = 15 + 15

6 . x = 30

x = 30 : 6

x = 5

b) 2 . x + 3 = 9

2 . x = 9 - 3

2 . x = 6

x = 6 : 2

x = 3

c) 17 - 6 : x = 15

6 : x = 17 - 15

6 : x = 2

x = 6 : 2

x = 3

d) x : 3 + 12 = 14

x : 3 = 14 - 12

x : 3 = 2

x = 2 . 3

x = 6

\(\dfrac{-1}{24}-\left[\dfrac{1}{4}-\left(\dfrac{1}{2}-\dfrac{7}{8}\right)\right]\)

\(=\dfrac{-1}{24}-\left[\dfrac{1}{4}\left(\dfrac{4}{8}-\dfrac{7}{8}\right)\right]\)

\(=\dfrac{-1}{24}-\left[\dfrac{1}{4}.\dfrac{-3}{8}\right]\)

\(=\dfrac{-1}{24}-\dfrac{-3}{32}\)

\(=\dfrac{-1}{24}+\dfrac{3}{32}\)

\(=\dfrac{5}{96}\)

Chúc bạn học tốt

My father lives in a house near the river because he likes swimming.

\(\dfrac{2}{15}:\left(-5\dfrac{4}{5}\right).2\dfrac{5}{12}\)

\(=\dfrac{2}{15}:\dfrac{-29}{5}.\dfrac{29}{12}\)

\(=\dfrac{2}{15}.\dfrac{-5}{29}.\dfrac{29}{12}\)

\(=\dfrac{2.\left(-5\right).29}{15.29.12}=\dfrac{-1}{18}\)

a) \(\dfrac{8}{15}+5=\dfrac{8}{15}+\dfrac{75}{15}=\dfrac{83}{15}\)

b) \(4-\dfrac{7}{3}=\dfrac{12}{3}-\dfrac{7}{3}=\dfrac{5}{3}\)

c) \(\dfrac{1}{2}\times8=\dfrac{1\times8}{2}=\dfrac{8}{2}=4\)

d) \(\dfrac{4}{9}:2=\dfrac{4}{9}\times\dfrac{1}{2}=\dfrac{4}{18}=\dfrac{2}{9}\)

e) ( Vì bạn ghi dấu không rõ nên mik làm 2 cách, trúng câu nào thì bạn ghi vô nhé. )

+) \(\dfrac{3}{14}:\dfrac{1}{2}=\dfrac{3}{14}\times2=\dfrac{3}{7}\)

+) \(\dfrac{3}{14}+\dfrac{1}{2}=\dfrac{3}{14}+\dfrac{7}{14}=\dfrac{10}{14}=\dfrac{5}{7}\)

Chúc bạn học tốt

\(250\times5\times0,2\)

\(=250\times\left(5\times0,2\right)\)

\(=250\times1\)

\(=250\)