= 2020 x 0,56 + 0,34 x 3 x 2020 + 2020 x 4 x 0,85 + 2020 x 5,02

= 2020 x 0,56 + 1,02 x 2020 + 2020 x 3,4 + 2020 x 5,02

= 2020 x ( 0,56 + 1,02 + 3,4 + 5,02 )

= 2020 x ( 1,58 + 3,4 + 5,02 )

= 2020 x ( 4,98 + 5,02 )

= 2020 x 10

= 20202

         ------------------Hết------------------       

Tính theo tính nhanh_________

6: \(9,5\times4,7+9,5\times4,3+9,5\)

\(=9,5\times\left(4,7+4,3+1\right)\)

\(=9,5\times10=95\)

5: \(32\times1,25\times2,5+0,476+0,524\)

\(=80\times1,25+1\)

=100+1

=101

4: \(3,5\times0,5+3,5\times0,125+3,5\times22,5\times4\)

=3,5x(90+0,5+0,125)

=3,5x90,625

=317,1875

3: \(32\times1,25\times2,5+\frac{54}{10}\times8,7+5,4\times3,3-10,8\)

\(=40\times2,5+5,4\times8,7+5,4\times3,3-5,4\times2\)

=100+5,4x(8,7+3,3-2)

=100+5,4x10

=100+54

=154

2: \(15,25\times0,5+15,25\times0,25+15,25\times0,125+15,25\times6\)

=15,25x(0,5+0,25+0,125+6)

=15,25x6,875

=104,84375

1: 2020x0,56+0,34x6060+8080x0,85+2020x5,02

=2020x0,56+2020x1,02+2020x3,4+2020x5,02

=2020x(0,56+1,02+3,4+5,02)

=2020x10

=20200

B=2021 x 13 + 2009 + 2020 x 2007/2020 + 2020 x520x2020

B=2021 x 13 +2009+2020/1x2007/2020 +2020x520x2020

B=26273+2009+2020¹/1x2007/2020¹+2121808000

B=28282+2007+2121808000

B=2121838289

\(x\times2020-x=2020\times2018+2020\)

\(\Rightarrow x\times\left(2020-1\right)=2020\times\left(2018+1\right)\)

\(\Rightarrow x\times2019=2020\times2019\)

\(\Rightarrow x=2020\)

x * 2020 - x = 2020 * 2018 + 2020

x * 2020 - x * 1 = 2020 * 2018 + 2020 * 1

x * ( 2020 - 1) = 2020 * (2018 + 1)

x * 2019 = 2020 * 2019

Vậy x = 2020

 2020 x 2021 - 3031  = 2020 x ( 2 + 2019 ) - 3031 = 2020 x 2019 + 2020 x 2 - 3031 = 2019 x 2020 + 1009

Nên ( 2019 x 2020 + 1009 ) : ( 2020  x 2021 - 3031 ) = ( 2019 x 2020 + 1009 ):( 2019 x 2020 + 1009 )=1

   2020 × 2021 - 1000 - 2020 × 2019 - 1020

= 2020 × 2021 - 2020 × 2019 - 1000 - 1020

= 2020 × 2021 - 2020 × 2019 - (1000 + 1020)

= 2020 × 2021 - 2020 × 2019 - 2020

= 2020 × 2021 - 2020 × 2019 - 2020 × 1

= 2020 × (2021 - 2019 - 1)

= 2020 × 1

= 2020.

Kết quả là:0

( 35 x 18 - 9 x 70 ) x 2010 x 2011 x ... x 2020

= (35 x 18 - 9 x 35 x 2) x 2010 x 2011 x ... x 2020

= ( 35 x 18 - 18 x 35 ) x 2010 x 2011 x ... x 2020

= 35 x (18 - 18 ) x 2010 x 2011 x ... x 2020

= 35 x 0 x 2010 x 2011 x ... x 2020 

= 0 x 2010 x 2011 x ... x 2020 

= 0

Ta có: 1 + ( 1  + 2 ) + ( 1 + 2 + 3 ) + ... + ( 1 + 2 + 3 +...+ 2020) 

= ( 1 + 1 + 1 +... + 1 ) + (2 + 2 +...+ 2 ) + ( 3 + 3+...+ 3 ) + ...+ 2020

Có 2020 số 1 ; 2019 số 2 ; 2018 số 3 ;... ; 1 số 2020 

=  2020 x 1 + 2019 x 2 + 2018 x 3 + ... + 2020x 1

=> \(M=\frac{1+\left(1+2\right)+\left(1+2+3\right)+...+\left(1+2+3+...+2020\right)}{1\times2020+2\times2019+...+2020\times1}\)

= \(\frac{1\times2020+2\times2019+...+2020\times1}{1\times2020+2\times2019+...+2020\times1}=1\)

yynbjkgyg

x= 2002/3000

ko bt đúng ko mong bn nhắc nhở