![](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)
20 - [ 30 - ( 5 - 1 ) ^2 : 2 ]
= 20 - [ 30 - 4^2 : 2 ]
= 20 - [ 30 - 16 : 2 ]
= 20 - [ 30 - 8 ]
= 20 - 22
= (-2)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) (4+5)2 = 92 = 81
42 + 52 = 16 + 25 = 41
Vì 81 > 41 nên (4+5)2 > 42 + 52.
b) 230 = (23)10 = 810
320 = (32)10 = 910.
Vì 8 < 9 nên 810 < 910 => 230 < 320
a) (4+5)2 = 92 = 81
42 + 52 = 16 + 25 = 41
Vì 81 > 41 nên (4+5)2 > 42 + 52.
b) 230 = (23)10 = 810
320 = (32)10 = 910.
Vì 8 < 9 nên 810 < 910 => 230 < 320
P/s tham khảo nha
![](https://rs.olm.vn/images/avt/0.png?1311)
M = \(\frac{1}{2}\)+ \(\frac{1}{6}\)+ \(\frac{1}{12}\)+ \(\frac{1}{20}\)+ \(\frac{1}{30}\)+ \(\frac{1}{42}\)
= \(\frac{6}{7}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
20 - [30 - 5 (5 - 1)2]
= 20 - [30 - 5 . 42]
= 20 - [30 - 5 . 16]
= 20 - [30 - 80]
= 20 - (- 50)
= 70
![](https://rs.olm.vn/images/avt/0.png?1311)
20 - [ 30 - ( 5 - 4 ) 2 : 2 ]
= 20 - [30 - 12 : 2]
= 20 - (30 - \(\frac{1}{2}\))
= 20 - 29,5
= -9,5
![](https://rs.olm.vn/images/avt/0.png?1311)
\(A=5+5^2+5^3+...+5^{20}\)
\(\Rightarrow A=\left(5+5^2\right)+\left(5^3+5^4\right)+...+\left(5^{19}+5^{20}\right)\)
\(\Rightarrow A=\left(5+25\right)+5^2.\left(5+5^2\right)+...+5^{18}.\left(5+5^2\right)\)
\(\Rightarrow A=30+5^2.30+...+5^{18}.30\)
\(\Rightarrow A=\left(1+5^2+...+5^{18}\right).30⋮30\)
\(\Rightarrow A⋮30\)
\(\Rightarrow A\) là bội của 3
Vậy...
![](https://rs.olm.vn/images/avt/0.png?1311)
a)=3.10-16:4
=30-4=26
b)=8.17-8.14
=8.(17-14)=8.3=24
c)=20-(30-16)
=20-14=6
d)=1008-17119:(119-102)
=1008-17119:17
=1008-1007=1
tính phếp toán sau
a,1008-17119 : [119-714:7] =
b 128. 430 - 6795 + 675 - 34125 : 375 =
c 5871:103+[247-82] . 5-1=
![](https://rs.olm.vn/images/avt/0.png?1311)
A) 3 . \(5^2\)- 16 : \(2^2\)= 3 . 25 - 16 : 4 = 75 - 4 = 71
B) 20 - [30-(5-\(1^2\)) ] = 20 - [30- (5-1) = 20 - [30 - 4 ] = 20 - 26 = -6
C) 22 . 7 - 23 . 14 = 22 . 17 - 8 = 364 - 8 = 356
D) 17.85 + 15.17-120 = 17 . ( 85 + 15 ) -120= 17 . 100 -120 = 1700 - 120 = 1580
k cho mính nhé bn
\(20-\left[30-\left(5-2\right)^2:2\right]\\ =20-\left(30-3^2:2\right)\\=20-\left(30-9:2\right)\\ =20-\left(30-4,5\right)\\ =20-25,5\\ =-5,5 \)