\(2019+2019+2019+2019+2019x7-2019\)

\(=2019x\left(7+4-1\right)\)

\(=2019x10=20190\)

20190

tra gg là ra á

( - 2019 - 2019 - 2019 - 2019 ) x ( -25 ) 

= (-4 ) x 2019 x ( - 25 ) 

= ( -4 ) x ( -25 ) 2019 

= 100 x 2019 

= 201900 

học tốt 

201900

Sai môn!

\(3876.2019+2019.6123+2019=2019\left(3876+6123+1\right)\)

                                                                        \(=2019.10000=20190000\)

Bài làm:

Ta có: \(3876.2019+2019.6123+2019\)

\(=2019.\left(3876+6123+1\right)\)

\(=2019.10000\)

\(=20190000\)

\(3876.2019+2019.6123+2019\)

\(=2019.\left(3876+6123+1\right)\)

\(=2019.10000\)

\(=20190000\)

(1/2019)^2020 . 2019^2019

= \(\frac{1}{2019^{2020}}\cdot2019^{2019}\)

= \(\frac{2019^{2019}}{2019^{2020}}\)

=1/2019

vậy.......

hok tốt

Thanks

Trả lời :...............................................

\(\frac{4078379}{4078379}\)

Hk tốt,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

k nhé Kim Râu La

\(\frac{2019}{1\times2}+\frac{2019}{2\times3}+\frac{2019}{3\times4}+...+\frac{2019}{2018\times2019}\)

\(=2019\left(\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}+...+\frac{1}{2018\times2019}\right)\)

\(=2019\left(\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{2018}-\frac{1}{2019}\right)\)

\(=2019\left(1-\frac{1}{2019}\right)\)

\(=2019\left(\frac{2019}{2019}-\frac{1}{2019}\right)\)

\(=2019\times\frac{2018}{2019}\)\(=\frac{2019\times2018}{2019}=2018\)

a) (4+4)x(2019 +2019 +.....+2019)

= 8 x 125 x 2019

= (8 x 125) x 2019

= 1000 x 2019

= 2019000

b) ( 42+42+...+42)+(125+125+....+125)

= 42 x 125 + 58 x 125

= 125 x ( 42 + 58)

= 125 x 100

= 12500

 42+42+...+42)+(125+125+....+125)

= 42 x 125 + 58 x 125

= 125 x ( 42 + 58)

= 125 x 100

= 12500

Tính bằng cách thuận tiện nhất.

2019 + 2019 +2019 + 2019 + 2019 x 7 - 2019

= 2019 x ( 7 +1 +1+1 - 1 ) = 2019 x 10 = 20190