A new road is being built outside the city

A meeting was being held when it began to rain

A report is being prepared by my friend when the lights go out

3.C

2.A

4.D

3 .C

\(\Leftrightarrow\dfrac{2\left(3x-1\right)-3\left(x-2\right)-8}{8}>\dfrac{4\left(5-3x\right)}{8}\)

\(\Leftrightarrow2\left(3x-1\right)-3\left(x-2\right)-8>4\left(5-3x\right)\)

\(\Leftrightarrow6x-2-3x+6-8>20-12x\)

\(\Leftrightarrow15x>24\)

\(\Leftrightarrow x>\dfrac{8}{5}\)

Vậy \(S=\left\{x|x>\dfrac{8}{5}\right\}\)

\(\dfrac{3x-1}{4}-\dfrac{3\left(x-2\right)}{8}-1>\dfrac{5-3x}{2}\)

\(\Leftrightarrow\dfrac{2\left(3x-1\right)}{8}-\dfrac{3\left(x-2\right)}{8}-\dfrac{8}{8}>\dfrac{4\left(5-3x\right)}{8}\)

\(\Leftrightarrow6x-2-3x+6-8>20-12x\)

\(\Leftrightarrow3x-4>20-12x\)

\(\Leftrightarrow3x+12x>20+4\)

\(\Leftrightarrow15x>24\)

\(\Leftrightarrow x>\dfrac{8}{5}\)

Vậy...

a.b.\(n_{Fe_2O_3}=\dfrac{48}{160}=0,3mol\)

\(Fe_2O_3+3H_2\rightarrow\left(t^o\right)2Fe+3H_2O\)

   0,3      0,9              0,6           0,9          ( mol )

\(m_{Fe}=0,6.56=33,6g\)

\(V_{H_2}=0,9.22,4=20,16l\)

c.\(2H_2+O_2\rightarrow\left(t^o\right)2H_2O\)

              0,9               1,8     ( mol )

\(V_{O_2}=0,9.22,4=20,16l\)

câu 4

Zn+2Hcl->ZnCl2+H2

0,1--0,2---------------0,1

n Zn=\(\dfrac{6,5}{65}\)=0,1 mol

=>HCl dư

m HCl=0,05.36,5=1,825g

=>VH2=0,1.22,4=2,24l

bài5

4Al+3O2-to>2Al2O3

0,2----0,15

2KMnO4-to>K2MnO4+MnO2+O2

0,3-------------------------------------0,15

n Al=\(\dfrac{5,4}{27}\)=0,2 mol

VO2=0,15.22,4=3,36l

=>m KMnO4=0,3.158=47,4g

8 We had had some problems, we decided to go on a trip to Hue

9 The students wrote their assignments, they had read some materials

10 After he had watched the football match, he wrote a report

B

B nhé bạn! Tick mình

B