Question

Tính nhanh:

a) 1/10000 + 13/10000 + 25/10000 + .... + 97/10000 + 109/10000

b) 4/3 x 2019 x 0,75

c) 4 x 5x 0,25 x 1/5 x 1/2 x 2

d) 2003 x 1999-2003-999/2004 x 999 + 1004

Giúp em với ạ

Answer 1

a)\(\dfrac{1}{10000}+\dfrac{13}{10000}+\dfrac{25}{10000}+...+\dfrac{97}{10000}+\dfrac{109}{10000}\)

\(=\dfrac{1+13+25+...+97+109}{10000}\)

\(=\dfrac{\left(1+109\right)\left[109-1\right]:12+1}{20000}\)

\(=\dfrac{110.10}{20000}=\dfrac{11}{200}\)

b)\(\dfrac{4}{3}\times2019\times0,75\)

=\(\dfrac{4}{3}\times\dfrac{3}{4}\times2019\)

\(=2019\)

c)\(4\times5\times0,25\times\dfrac{1}{5}\times\dfrac{1}{2}\times2\)

\(=\left(4\times\dfrac{1}{4}\right)\left(5\times\dfrac{1}{5}\right)\left(2\times\dfrac{1}{2}\right)\)

\(=1\times1\times1=1\)

Ý d) đặt tính kiểu gì thế ?

Answer 2

2023 rồi còn ai ở đây ko 😢😢😢