2020x(45+54+1)

2020x100

202000

2020x45+2020x54+2020

=2020x(45+54)

=2020x99

=199980

hellp !!

= 1999000 nhé! Nhớ k cho mình nha!

  1999 x 867 + 2000 x 133 - 133

= 1999 x 867 + 2000 x 133 - 133 x 1 

= 1999 x 867 + 133 x ( 2000 - 1 )

= 1999 x 867 + 133 x 1999

= 1999 x ( 867 + 133 ) 

= 1999 x 1000

= 1999000

như vậy cũng đúng

\(25\times32\times125\times15\\=(25\times4)\times(8\times125)\times15\\=100\times1000\times15\\=100000\times15\\=1500000\)

25 x 32 x 125 x 15 

=(125 x 32 ) x (25 x 15 )

= 4000 x 375

=1 500 000

12,35 + 1,42 - 11,35 + 8,58

= (12,35 - 11,35) + (1,42 + 8,58)

= 1 + 10

= 11

12,35 + 1,42 - 11,35 + 8,58 
= 12,35 + (1,42 - 11,35 ) + 8,58 
= 12,35 - 9,93 + 8,58 
= 2,42 + 8,58 
= 11

(999+51)+(362+654398)

=1050+654760

=655810

     654398 + 362 + 999 + 51

= ( 654398 + 362 ) + ( 999 + 51 )

= 654760 + 1050

= 655810

2 600 000 m² + 58 700 m² + 400 000 m² + 1 300 m² =

(2 600 000 m²  + 400 000 m²) + (58 700 m² + 1 300 m²)=

3 000 000 m² + 7 000 m² = 

3 007 000 m²

 A = 24 x 73 + 12 x 90 - 24 x 18

 A = 24 x 73 + 12 x 2 x 45 - 24 x 18

 A = 24 x 73 + 24 x 45 - 24 x 18

 A = 24 x ( 73 + 45 - 18 )

 A = 24 x 100

A = 2400

6,8 x 115,2 - 15,2 x 6,8

= 6,8 x (115,2 - 15,2)

= 6,8 x 100

= 680

\(6,8\times115,2-15,2\times6,8\)

\(=6,8\times\left(115,2-15,2\right)\)

\(=6,8\times100\)

\(=680\)