Question

thực hiện các phép tính sau một cách hợp lí

a,\(\dfrac{1}{5}+\dfrac{4}{10}+\dfrac{51}{85}+\dfrac{28}{35}\)

Answer 1

=(1/5+3/5+4/5+2/5)

=10/5=2

Answer 2

\(=\dfrac{1}{5}+\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{4}{5}=\dfrac{10}{5}=2\)

Answer 3

=1/5+2/5+51/85+4/5

=7/5+51/85

=119/85+51/85

=170/85=2

Answer 4

\(\dfrac{1}{5}+\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{4}{5}=\dfrac{10}{5}=2\)

Answer 5

a, = ( 1/5 + 28/35 ) + ( 51/85 + 4/10 )

= 1 + 1

= 2

Answer 6

a) \(\dfrac{1}{5}+\dfrac{4}{10}+\dfrac{51}{85}+\dfrac{28}{35}\)

\(=\left(\dfrac{1}{5}+\dfrac{28}{35}\right)+\left(\dfrac{4}{10}+\dfrac{51}{85}\right)\)

\(=1+1\)

\(=2\)