1 và 13/18 - ( 15/16 - 13/6 ) + 5/18 tính hợp lí các bạn giúp mình với ạ . Cảm ơn mn nhìu
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)
Ta có: \(A=1-2+3-4+5-6+7-8+9\)
\(=(1+9)-(2+8)+(3+7)-(4+6)+5\)
\(=10-10+10-10+5\)
\(=5\)
Vậy \(A=5\)
B = 12 - 14 + 16 - 18 + ... + 2008 - 2010
B = -2 + (-2)+ (-2)+ (-2) + ...+ (-2)
B = -2 . 100
B = -200
![](https://rs.olm.vn/images/avt/0.png?1311)
`Answer:`
\(12x-144=0\)
\(\Leftrightarrow12x=144\)
\(\Leftrightarrow x=144:12\)
\(\Leftrightarrow x=12\)
\(5x-32:18=13\)
\(\Leftrightarrow5x-\frac{16}{9}=13\)
\(\Leftrightarrow5x=13+\frac{16}{9}\)
\(\Leftrightarrow5x=\frac{133}{9}\)
\(\Leftrightarrow x=\frac{133}{9}:5\)
\(\Leftrightarrow x=\frac{133}{45}\)
\(3x+6=15\)
\(\Leftrightarrow3x=9\)
\(\Leftrightarrow x=3\)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
-3/11.(-22)/66.121/15
=(-3).(-22).121
11.66.15
=11
15
3/7.2/5.7/3.20.19/72
=3.2.7.20.19
7.5.3.72
=76
16
6/7.8/13+6/13.9/7-3/13.6/7
=6/7.8/13+6/7.9/13-3/13.6/7
=6/7.(8/13+9/13-3/13)
=6/7.14/13
=12/13
-1/4.152/11+68/4.(-1)/11
=152/4.(-1)/11+68/4.(-1)/11
=(-1)/11.(152/4+68/4)
=(-1)/11.220/4
=-110/22
-5/7.2/11+(-5)/7.9/11+12/7
=-5/7.2/11+-5/7.9/11+12/7
=-5/7.(2/11+9/11)+12/7
=-5/7.1+12/7
=(-5)/7+12/7
=7/7
=1
146/13-(18/7+68/13)
=146/13-18/7-68/13
=(146/13-68/13)-18/7
=78/13-18/7
=6-18/7
=42/7-18/7
=24/7
tính nhanh:
181+3-4-5+6+7-8-9+10+11-12-13+14+15-16-17+18+19
các bạn giải đầy đủ ra giúp mình với nhé!
![](https://rs.olm.vn/images/avt/0.png?1311)
=181+(3-4-5+6)+(7-8-9+10)+(11-12-13+14)+(15-16-17+18)+19
=181+0+0+0+0+19
=181+19
=200
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\frac{4}{5}+\frac{3}{15}=\frac{4}{5}+\frac{1}{5}=\frac{4+1}{5}=\frac{5}{5}=1\)
\(\frac{2}{3}+\frac{32}{24}=\frac{2}{3}+\frac{4}{3}=\frac{2+4}{3}=\frac{6}{3}=2\)
\(\frac{5}{6}+\frac{15}{18}=\frac{5}{6}+\frac{5}{6}=\frac{5+5}{6}=\frac{10}{6}\)
HT
= 31/18 - ( 15/16- 13/16 ) + 5/18
= ( 31/18 + 5/18 ) - ( 15/16 -13/16)
=2 -1/8
=15/8
= 31/18-(15/16-13/16)+5/18
= ( 31/18+5/18 ) - ( 15/16- 13/16
= 2-1/8
=15/8