![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
1-2-3-4+5-6-7-8+9-10-11-12+...+97-98-99-100
=(1-2-3-4)+(5-6-7-8-)+(9-10-11-12)+....+(97-98-99-100)
=(-8)+(-16)+(-24)+.....+(-200)
=(-8).(1+2+3+4+.....+25)
=(-8).325
=(-2600)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\frac{1}{10}+\frac{1}{30}+\frac{1}{60}+\frac{1}{100}+\frac{1}{150}\)
= \(\frac{1}{10}.\left(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}\right)\)
= \(\frac{1}{10}.2.\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}\right)\)
= \(\frac{1}{5}.\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}\right)\)
= \(\frac{1}{5}.\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}\right)\)
= \(\frac{1}{5}.\left(1-\frac{1}{6}\right)\)
= \(\frac{1}{5}.\frac{5}{6}\)
= \(\frac{1}{6}\)
\(\frac{1}{10}+\frac{1}{30}+\frac{1}{60}+\frac{1}{100}+\frac{1}{150}\)
\(=\frac{1}{10}.\left(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}\right)\)
\(=\frac{1}{10}.2.\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}\right)\)
\(=\frac{1}{10}.2.\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}\right)\)
\(=\frac{1}{10}.2.\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}\right)\)
\(=\frac{1}{5}.\left(1-\frac{1}{6}\right)\)
\(=\frac{1}{5}.\frac{5}{6}\)
\(=\frac{1}{6}\)
Rất vui vì giúp đc bạn <3
![](https://rs.olm.vn/images/avt/0.png?1311)
1+4+5+9+...+60+97
=1+4+1+4+4+5+5+9+9+14+14+23+23+37+37+60
=2.(1+4+5+9+14+23+37)+60
=2.93+60
=186+60
=246
chúc bạn học tốt nha
ủng hộ mk với nha
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
3.6.(-10)+60.(-97)
=3.[6.(-10)]+60.(-97)
=3.(-60)+60.(-97)
=[3.(-97)]+[(-60)+60]
=-291+0=-291
3.6.(-10)+60.(-97)
=(-3).6.10+60.(-97) (áp dụng dấu khi nhân số nguyên)
=(-3).(6.10)+60.(-97)
=(-3).60+60.(-97)
=60{(-3)+(-97)} (mk không biết viết dấu ngoặc vuông)
=60.(-100)
=-6000