Question

a)  2/5  × x =4

b)      8/7 : x = 4/5

Answer 1

\(a,x=4:\dfrac{2}{5}\\ x=4.\dfrac{5}{2}\\ x=\dfrac{20}{2}\\ x=10\\ b,x=\dfrac{8}{7}:\dfrac{4}{5}\\ x=\dfrac{8}{7}.\dfrac{5}{4}\\ x=\dfrac{10}{7}\)

Answer 2

a)

\(\dfrac{2}{5}\cdot x=4\)

\(x=4:\dfrac{2}{5}=>x=10\)

. là dấu nhân nhé

b)

\(\dfrac{8}{7}:x=\dfrac{4}{5}\)

\(x=\dfrac{8}{7}:\dfrac{4}{5}=>x=\dfrac{10}{7}\)

Answer 3

a) x = 4 : 2/5

x= 4. 5/2

x= 10

b) x= 8/7 : 4/5

x= 8/7. 5/4

x= 10/7

Answer 4

Answer 5

\(a,\dfrac{2}{5}\times x=4\)  

   \(x=4:\dfrac{2}{5}\)

   \(x=4\times\dfrac{5}{2}\)  

   \(x=10\)     

\(b,\dfrac{8}{7}:x=\dfrac{4}{5}\) 

    \(x=\dfrac{8}{7}:\dfrac{4}{5}\)  

    \(x=\dfrac{8}{7}\times\dfrac{5}{4}\)

    \(x=\dfrac{10}{7}\)                                                         

Answer 6

x = 4 : \(\dfrac{2}{5}\)
x = 4 x 5 : 2

x = 10