Question

Answer 1

Bài 2: 

a: \(\Leftrightarrow x\cdot\dfrac{1}{5}=\dfrac{25}{30}-\dfrac{19}{30}=\dfrac{6}{30}=\dfrac{1}{5}\)

hay x=1

b: \(\Leftrightarrow x\cdot\dfrac{1}{15}=\dfrac{9}{15}-\dfrac{10}{15}=\dfrac{-1}{15}\)

hay x=-1

c: \(\Leftrightarrow\dfrac{85}{x}=\dfrac{33}{24}+\dfrac{52}{24}=\dfrac{85}{24}\)

hay x=24

d: \(\Leftrightarrow x\cdot\dfrac{1}{3}=\dfrac{7}{6}+\dfrac{15}{6}=\dfrac{22}{6}=\dfrac{11}{3}\)

hay x=11

Answer 2

CÂU 1

a \(x=\dfrac{2}{11}+\dfrac{1}{5}=\dfrac{21}{55}\)

b \(x=\dfrac{1}{4}\)

c \(x=\dfrac{13}{12}-\dfrac{7}{8}=\dfrac{5}{24}\)

d \(x=\dfrac{4}{27}+\dfrac{-6}{15}=\dfrac{-34}{135}\)

e x=\(x=\dfrac{3}{16}-\dfrac{1}{2}=\dfrac{-5}{16}\)

CÂU 2

a \(\dfrac{x}{5}=\dfrac{1}{5}\)

\(x=\dfrac{1}{5}\)x\(5\)

\(x=1\)

b \(\dfrac{x}{15}=\dfrac{-1}{15}\)

\(x=\dfrac{-1}{15}\)x\(5\)

\(x=-1\)

c \(\dfrac{85}{x}=\dfrac{85}{24}\)

\(x=\dfrac{2040}{85}=24\)

d \(\dfrac{x}{3}=\dfrac{7}{6}+\dfrac{5}{2}\)

\(\dfrac{x}{3}=\dfrac{11}{3}\)

\(x=\dfrac{33}{3}=11\)

 

Answer 3

a)\(x-\dfrac{1}{5}=\dfrac{2}{11}\)

=>\(x=\dfrac{2}{11}+\dfrac{1}{5}=\dfrac{10+11}{55}=\dfrac{21}{55}\)

b)\(x=\dfrac{-1}{2}+\dfrac{3}{4}=\dfrac{-2+3}{4}=\dfrac{1}{4}\)

Answer 4

c)\(x+\dfrac{7}{8}=\dfrac{13}{12}\)

=>\(x=\dfrac{13}{12}-\dfrac{7}{8}=\dfrac{26}{24}-\dfrac{21}{24}=\dfrac{5}{24}\)

d)\(x-\dfrac{-6}{15}=\dfrac{4}{27}\)

=>\(x=\dfrac{4}{24}+\dfrac{-6}{15}=\dfrac{20}{120}-\dfrac{48}{120}=\dfrac{-28}{120}=\dfrac{-7}{30}\)