Предмет: Математика, автор: zamur1

решить 1/67+1/78+...+ 1/49*50=

Ответы

Автор ответа: dtnth

$\frac{1}{6*7}+\frac{1}{7*8}+...+\frac{1}{49*50}=\\\\\frac{7-6}{6*7}+\frac{8-7}{7*8}+...+\frac{50-49}{49*50}=\\\\\frac{7}{6*7}-\frac{6}{6*7}+\frac{8}{7*8}-\frac{7}{7*8}+...+\frac{50}{49*50}-\frac{49}{49*50}=\\\\\frac{1}{6}-\frac{1}{7}+\frac{1}{7}-\frac{1}{8}+\frac{1}{8}-\frac{1}{9}+...+\frac{1}{49}-\frac{1}{50}=\\\\\frac{1}{6}-\frac{1}{50}=\frac{1*25}{6*25}-\frac{1*3}{50*3}=\frac{25-3}{150}=\frac{22}{150}=\frac{11}{75}$
ответ: 11/75

Предыдущий вопрос

Следующий вопрос

Интересные вопросы

Предмет: Английский язык, автор: Wolf3311

срочно!!!!!!!!!!!! ask for her parent's permission .Ask for some pocket money .Wear her jeans and T-shirt . Wear her best clothes . Take some anynfood with her.Buy a hamburger at the zoo.Buy an ice cream buy some souvenirs.Feed animals take photos follow the zoo rules

2 года назад

Предмет: Английский язык, автор: liya20001

помогите пожалуйста с английским

2 года назад

Предмет: Английский язык, автор: annystenova13

Cat (1) __there lived a cat. His name was Tiger. He (2)__ my friends pet. One day Tiger (3) __ over the wall and (4) ___ into the garden next door. He (5)___ a bird in an apple tree. It was a small brown bird with bright red (6) __ on (7)___ chest. Tiger was hungry. He climbed the tree. The bird did not see (8) ___. The bird was at the end of a long, thin branch. It sang(9) ___. 1.One 2.Be 3.Jump 4.Go 5.See 6.Feather 7.It 8.He 9.pretty

2 года назад