Question

a 3/8 : 2/5 + 5,8 : 2/5

b (13,8 x 2,4 ) x (2,25 - 1,5 x 1,5 )

Answer 1

a \(\dfrac{3}{8}\times\dfrac{5}{2}+\dfrac{5}{8}\times\dfrac{5}{2}=\dfrac{5}{2}\left(\dfrac{3}{5}+\dfrac{5}{8}\right)=\dfrac{5}{2}\times\dfrac{8}{8}=\dfrac{5}{2}\times1=\dfrac{5}{2}\)

b \(33.12\times0=0\)

Answer 2

a) = (3/8 + 5,8) : 2/5 = 107/8 : 2/5 = 535/16

b) = 33,12 x 0 = 0

Answer 3

a 3/8 : 2/5 + 5,8 : 2/5

 3/8 x 5/2 + 5,8 x 5/2

= 5/2 x ( 3/8 + 5.8)

= 5/2 x  6,175

= 247/16

nếu chỗ 5,8 bn ghi sai thì mik sửa đề thành 3/8 : 2/5 + 5/8 : 2/5

3/8 x 5/2 + 5/8 x 5/2

=  5/2 x ( 3/8 + 5/8)

= 5/2 x 1

=5/2

 

 

b (13,8 x 2,4 ) x (2,25 - 1,5 x 1,5 )

= 33.12 x 0

= 0