Question

Tìm X: a)X+1/4×1/5=4/5 b)3 2/3 : X=2 2/3 - 1 1/2

Answer 1

a)

`x+1/4xx1/5=4/5`

`x+1/20=4/5`

`x=4/5-1/20`

`x=16/20-1/20`

`x=15/20=3/4`

b)

`3 2/3:x=2 2/3-1 1/2`

`11/3:x=8/3-3/2`

`11/3:x=16/6-9/6`

`11/3:x=7/6`

`x=11/3:7/6`

`x=11/3xx6/7`

`x=22/7`

Answer 2

\(a,x+\dfrac{1}{4}.\dfrac{1}{5}=\dfrac{4}{5}\)

\(\Rightarrow\)\(x+\dfrac{1}{20}=\dfrac{4}{5}\)

\(\Rightarrow x=\dfrac{4}{5}-\dfrac{1}{20}=\dfrac{16}{20}-\dfrac{1}{20}=\dfrac{3}{4}\)

\(b,3\dfrac{2}{3}:x=2\dfrac{2}{3}-1\dfrac{1}{2}\)

\(\Rightarrow\dfrac{11}{3}:x=\dfrac{7}{6}\)

\(\Rightarrow x=\dfrac{11}{3}:\dfrac{7}{6}=\dfrac{22}{7}\)