5715 + 127 + 285 - 27

= (5715 + 285) + (127 - 27)

= 6000 + 100

= 6100

\(5715+127+285-27\)

\(=\left(5715+285\right)+\left(127-127\right)\)

\(=6000+100\)

\(=6100\)

$5715+127+285-27$

$=\left(5715+285\right)+\left(127-127\right)$

$=6000+100$

$=6100$

so sáng qua phân số trung gian: \(\dfrac{47}{73}\)

có

\(\dfrac{47}{70}>\dfrac{47}{73}\)

\(\dfrac{39}{73}< \dfrac{47}{73}\)

\(=>\dfrac{47}{70}>\dfrac{39}{73}\)

Ta có:
\(\dfrac{47}{70}>\dfrac{47}{73}\)
\(\dfrac{47}{73}>\dfrac{39}{73}\)
\(\Rightarrow\dfrac{47}{70}>\dfrac{39}{73}\)

125 125 x 127 - 127 127 x 125

⇒ Dấu cách là dấu gì hả bạn?

a, (1 + 3 + 5 + 7+ ... + 2003 + 2005) x (125125 x 127 - 127127 x125)

= (1 + 3 + 5 +...+2003 + 2005) x (125 x 1001 x 127 - 127x1001 x 125)

= (1 + 3 + 5 +...+ 2003 + 2005) x 0

= 0 

b; 1000 x 0,04 - 100 : 2,5 + 10 x 0,4

= 100 x 0,4 - 100 x 0,4 + 10 x 0,4

= 0 + 4

= 4 

\(1357\times28+73\times1357-1357=1357\times\left(28+73-1\right)=1357\times100=135700\)

= 1357(28+73-1)
= 1357x100
= 135700

= 1357 x (28 + 73) - 1357

= 135700