=10000

2000+2000+2000+2000+2000= 10000

=2000*5=10000

2000 + 2000 + 2000 + 2000 + 2000 = 2000 x 5

                                                    =      10000

2000 + 2000 + 2000 + 2000 + 2000 = 10000

tk cho mk với nha

= 10000

8000

k cho mình nhé

thank you

2000+2000+2000+2000

=2000 x 4

=8000

K mình nha

"." nhẹ hóng cao nhân :)) 

???????????????........................................

đây mà là toán lớp 1

\(\frac{2000}{1.2}+...+\frac{2000}{2002.2003}\)
\(=2000.\left(\frac{1}{1.2}+....+\frac{1}{2002.2003}\right)\)
\(=2000.\left(\frac{1}{1}-\frac{1}{2}+...+\frac{1}{2002}-\frac{1}{2003}\right) \)
\(=2000.\left(\frac{1}{1}-\frac{1}{2003}\right)=2000.\frac{2002}{2003}\)

đặt A=200/1.2+200/2.3+200/3.4+...+200/2002.2003

A:2000 = 1-1/2+1/2-1/3+...+1/2002-1/2003

A:2000=1-1/2003

A:2000=2002/2003

A=....

k nhe

\(S=2000.\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+...+\frac{1}{9900}\right)=2000.\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+....+\frac{1}{99.100}\right)\)

  \(=2000.\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+....+\frac{1}{99}-\frac{1}{100}\right)=2000.\left(1-\frac{1}{100}\right)=20.99=1980\)

3945

3945

7890 : 2 = 3945

=40           

40 nhé