Question

 Tính nhanh: 
a, 5/6 x 4/5 + 4/5 x 1/6 + 4/5

b, 60 x (7/12 + 4/15)

Xin lời giải chi tiết ạ

 

Answer 1

A)4/5x (5/6+1/6)

   4/5x     1= 4/5

Answer 2

\(a,\dfrac{5}{6}\times\dfrac{4}{5}+\dfrac{4}{5}\times\dfrac{1}{6}+\dfrac{4}{5}=\dfrac{4}{5}\times\left(\dfrac{5}{6}+\dfrac{1}{6}+1\right)=\dfrac{4}{5}\times2=\dfrac{8}{5}\)

\(b,60\times\left(\dfrac{105}{180}+\dfrac{48}{180}\right)=60\times\dfrac{17}{20}=51\)

Answer 3

a) \(\dfrac{5}{6}\times\dfrac{4}{5}+\dfrac{4}{5}\times\dfrac{1}{6}+\dfrac{4}{5}\)

\(=\dfrac{5}{6}\times\dfrac{4}{5}+\dfrac{4}{5}\times\dfrac{1}{6}+\dfrac{4}{5}\times1\)

\(=\dfrac{4}{5}\times\left(\dfrac{5}{6}+\dfrac{1}{6}+1\right)\)

\(=\dfrac{4}{5}\times2\)

\(=\dfrac{8}{5}\)

b) \(60\times\left(\dfrac{7}{12}+\dfrac{4}{15}\right)\)

\(=60\times\dfrac{17}{20}\)

\(=\dfrac{1020}{20}\)

\(=51\)

Answer 4

\(\dfrac{5}{6}\)x\(\dfrac{4}{5}+\dfrac{4}{5}\)x\(\dfrac{1}{6}\)+\(\dfrac{4}{5}\)

=> \(\dfrac{5}{6}\)x\(\dfrac{4}{5}+\dfrac{4}{5}\)x\(\dfrac{1}{6}+\dfrac{4}{5}\)x1

=> \(\dfrac{4}{5}\)x\(\left(\dfrac{5}{6}+\dfrac{1}{6}+1\right)\)

=> \(\dfrac{4}{5}\)x2

=> \(\dfrac{8}{5}\)

b) 60 x\(\left(\dfrac{7}{12}+\dfrac{4}{15}\right)\)

=> 60 x \(\dfrac{17}{20}\)

=>51