= 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

2020 x 14 + 4040 x 16 + 6060 x 18

= 2020 x 14 + 2020 x 2 x 16 + 2020 x 3 x 18

= 2020 x 14 + 2020 x 32 + 2020 x 54

= 2020 x (14 + 32 + 54)

= 2020 x 100

= 202000

\(2020\times14+4040\times16+6060\times18\)

\(=2020\times14+2020\times2\times16+2020\times3\times18\)

\(=2020\times14+2020\times32+2020\times54\)

\(=2020\times\left(14+32+54\right)\)

\(=2020\times100\)

\(=202000\)

a) 2070 + 414 x 4 x 28 - 138 x 3 x 17 = 41400

b) 2020 x 14 + 4040 x 16 + 6060 x 18 = 72720

c) 42 x 477 + 14 x 336 x 3 + 84 x 92 - 42 = 41832

a) 2070 + 414 x 4 x 28 - 138 x 3 x 17 = 41400

b) 2020 x 14 + 4040 x 16 + 6060 x 18 = 72720

c) 42 x 477 + 14 x 336 x 3 + 84 x 92 - 42 = 41832

À ờm...đúng là sai thật, có thể ib mik gửi đề cho ạ

Đặt \(2020-x=u;x-2021=v\)thì \(u+v=-1\)

Phương trình trở thành \(\frac{u^2+uv+v^2}{u^2-uv+v^2}=\frac{19}{49}\Leftrightarrow30u^2+30v^2+68uv=0\)

\(\Leftrightarrow15\left(u+v\right)^2+4uv=0\Leftrightarrow4uv=-15\Leftrightarrow uv=\frac{-15}{4}\)

hay \(\left(2020-x\right)\left(x-2021\right)=-\frac{15}{4}\Leftrightarrow x^2-4041x+4082416,25=0\)

Dùng công thức nghiệm tìm được x = 2022, 5 hoặc x = 2018, 5

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