Question

Answer 1

Câu 1:

a) \(75+25.\left(\dfrac{1}{50}-3\right)\) 

\(=75+25.\dfrac{-149}{50}\) 

\(=75+\dfrac{-149}{2}\) 

\(=\dfrac{1}{2}\) 

b) \(\dfrac{3}{5}.\dfrac{19}{13}+\dfrac{-3}{5}.\dfrac{6}{13}-2\dfrac{3}{5}\) 

\(=\dfrac{3}{5}.\dfrac{19}{13}+\dfrac{3}{5}.\dfrac{-6}{13}-\dfrac{13}{5}\) 

\(=\dfrac{3}{5}.\left(\dfrac{19}{13}+\dfrac{-6}{13}\right)-\dfrac{13}{5}\) 

\(=\dfrac{3}{5}.1-\dfrac{13}{5}\) 

\(=\dfrac{3}{5}-\dfrac{13}{5}\) 

\(=-2\)

Answer 2

Giúp tui

Answer 3

Câu 10:

a) \(\dfrac{x}{3}-\dfrac{3}{4}=\dfrac{1}{12}\) 

            \(\dfrac{x}{3}=\dfrac{1}{12}+\dfrac{3}{4}\) 

             \(\dfrac{x}{3}=\dfrac{5}{6}\) 

⇒\(x=\dfrac{5.3}{6}=\dfrac{5}{2}\) 

b) \(\dfrac{17}{2}-\left|2x-\dfrac{5}{3}\right|=\dfrac{-7}{6}\) 

              \(\left|2x-\dfrac{5}{3}\right|=\dfrac{17}{2}-\dfrac{-7}{6}\) 

              \(\left|2x-\dfrac{5}{3}\right|=\dfrac{29}{3}\) 

\(\Rightarrow2x-\dfrac{5}{3}=\dfrac{29}{3}\) hoặc \(2x-\dfrac{5}{3}=\dfrac{-29}{3}\) 

              \(x=\dfrac{17}{3}\) hoặc \(x=-4\)

Answer 4

Làm tiếp câu 9:

c) \(\left(2\dfrac{1}{3}-\dfrac{1}{9}\right):\left(-2\dfrac{1}{6}+0,25\right)+1\dfrac{11}{19}\) 

\(=\left(\dfrac{7}{3}-\dfrac{1}{9}\right):\left(\dfrac{-13}{6}+\dfrac{1}{4}\right)+\dfrac{30}{19}\) 

\(=\dfrac{20}{9}:\dfrac{-23}{12}+\dfrac{30}{19}\) 

\(=\dfrac{-80}{69}+\dfrac{30}{19}\) 

\(=\dfrac{550}{1311}\)