Hộ e nốt ah
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
PT
2
HP
19 tháng 10 2021
a. Mg + 2HCl ---> MgCl2 + H2↑
b. Fe2O3 + 6HCl ---> 2FeCl3 + 3H2O
c. 2Al + 6HCl ---> 2AlCl3 + 3H2↑
d. 2C2H6 + 7O2 ---to---> 4CO2↑ + 6H2O
e. BaCl2 + 2AgNO3 ---> Ba(NO3)2 + 2AgCl↓
f. Al2(SO4)3 + 3Ba(OH)2 ---> 2Al(OH)3 + 3BaSO4↓
Trong đó:
to: nhiệt độ
↑: bay hơi
↓: kết tủa
(Câu f sai nên mik sửa từ Al2(SO4)3 thành Al(OH)3)
S
1
DT
Đỗ Thanh Hải
CTVVIP
6 tháng 6 2021
III
1 appreciated
2 worried
3 tense
4 confident
5 delighted
6 frustrated
7 calm
8 relaxed
9 self-disciplined
10 depressed
V
1 had resolved
2 has taken
3 Did you say
4 not to take
5 wanted
6 is being repaired
7 taking
8 to think
9 had worked
10 was washing - dropped
11 will find
12 faces
13 turned
14 to give
15 will empathise
3 tháng 9 2021
Đặt \(A=\dfrac{1}{\sqrt[3]{a+7b}}+\dfrac{1}{\sqrt[3]{b+7c}}+\dfrac{1}{\sqrt[3]{c+7a}}\)
\(A=\dfrac{\sqrt[3]{64}}{\sqrt[3]{8.8\left(a+7b\right)}}+\dfrac{\sqrt[3]{64}}{\sqrt[3]{8.8\left(b+7c\right)}}+\dfrac{\sqrt[3]{64}}{\sqrt[3]{8.8\left(c+7a\right)}}\)
\(\ge\dfrac{4}{\dfrac{8+8+a+7b}{3}}+\dfrac{4}{\dfrac{8+8+b+7c}{3}}+\dfrac{4}{\dfrac{8+8+c+7a}{3}}\ge\dfrac{\left(2+2+2\right)^2}{\dfrac{8+8+a+7b+8+8+b+7c+8+8+c+7a}{3}}\)
\(=\dfrac{36.3}{8\left(a+b+c\right)+48}=\dfrac{3}{2}\)
Vậy \(A_{min}=\dfrac{3}{2}\Leftrightarrow a=b=c=1\)
19 tháng 2 2022
4, were
5, was
6, were
7, was
8, were
9, was
10, were
11, were
12, was
13, was
14, was
TD
19 tháng 2 2022
4.was
5.was
6.were
7.was
8.were
9.was
10.were
11.were
12.was
13.was
14.was
HP
6 tháng 3 2022
Câu 4:
\(\dfrac{25}{26}-\dfrac{15}{26}=\dfrac{5}{13}\)
\(\dfrac{46}{39}-\dfrac{11}{13}=\dfrac{1}{3}\)
\(\dfrac{37}{45}-\dfrac{5}{9}=\dfrac{4}{15}\)
\(1-\dfrac{1}{3}=\dfrac{2}{3}\)
Câu 5:
Cạnh ngắn là:
\(2-\dfrac{1}{3}=\dfrac{5}{3}\left(m\right)\)
Chu vi hình bình hành là:
\(\left(2+\dfrac{5}{3}\right)\times2=\dfrac{22}{3}\left(m\right)\)
Nửa chu vi hình bình hành là:
\(\dfrac{22}{3}:2=\dfrac{11}{3}\left(m\right)\)
Chọn D
NV
Nguyễn Việt Lâm
Giáo viên
6 tháng 5 2021
Phương trình \(\Delta\) có dạng:
\(y=m\left(x+1\right)-2\Leftrightarrow y=mx+m-2\)
Phương trình hoành độ giao điểm (P) và \(\Delta\):
\(-\dfrac{1}{2}x^2=mx+m-2\Leftrightarrow x^2+2mx+2m-4=0\) (1)
\(\Delta'=m^2-2m+4=\left(m-1\right)^2+3>0\) ; \(\forall m\)
\(\Rightarrow\) (1) luôn có 2 nghiệm pb với mọi m hay (P) luôn cắt \(\Delta\) tại 2 điểm pb
b.
Theo hệ thức Viet: \(\left\{{}\begin{matrix}x_A+x_B=-2m\\x_Ax_B=2m-4\end{matrix}\right.\)
Đặt \(A=x_A^2x_B+x_Ax_B^2=x_Ax_B\left(x_A+x_B\right)\)
\(A=-2m\left(2m-4\right)=-4m^2+8m=-4\left(m-1\right)^2+4\le4\)
\(A_{max}=4\) khi \(m=1\)
V
1 has won
2 haven't seen
3 have taken
4 has visited
5 have read
41. A
42. B
V.
1. has won
2. haven't studied
3. have taken
4. has visited
5. have read