5.B

6.C

7.D

8.C

9.D

10.B

11.A

12.B

13.D

14.D

1D 2A 3D 4C 5B 6B 7B 8A 9A 10B 11B 12C 13D 14A 15D 16C

D - A 
D - C 
B - B - B - A - A - B - B - C - D - D - D - C

alternatively

symbolizes

hiking

inexperienced

attendances

believable

28.alternatively

29.symbolizes

30.hiking

31.inexperienced

32.attendances

33.believable

alternatively

symbolizes

hiking

inexperienced

attendances

believable

A - A 
A - B 
B - C - C - A - C - B - D - A - B - C - A - C

1.A

2.A 
3.A

4.B 
5.B

6.C

7.C

8. A

9. C

10. B

11. D

12.A

13. B

14. C

15. A

16. C

A - A 
A - B 
B - C - C - A - C - B - D - A - B - C - A - C

\(\left(-2023\right).2024-2023.\left(10-2024\right)\\ =-2023.2024-2023.10+2023.2024\\ =\left(2023.2024-2023.2024\right)-2023.10\\ =0-2023.10=-20230\\ ---\\ 198.246-246.\left(198-19\right)\\ =198.246-246.198+246.19\\ =0-246.19=-4674\\ ---\\ 297.\left(435-24\right)-435.\left(297-24\right)\\ =297.435-297.24-435.297+435.24\\ =\left(297.435-435.297\right)+\left(435.24-297.24\right)\\ =0+\left(435-297\right).24\\ =0+138.24=3312\\ ----\\ \left(-367\right).\left(19-198\right)+198.\left(19-367\right)\\ =-367.19+367.198+198.19-367.198\\ =\left(367.198-367.198\right)+\left(198.19-367.19\right)\\ =0+19.\left(198-367\right)=0+19.\left(-169\right)=-3211\)

1. B

2. C

3. C

4. B

5. A

6. D

7. C

8. C

9. A

10. B

1. B 2. C 3. C 4. B 5. A 6. D 7. C 8. C 9. A 10. B

a) \(k=-5\)

b) 

Tìm x xong rồi tìm y

3 thì làm kiểu gì cũng được

Bài 3:

Hình 1:

Xét ΔABC có \(\widehat{A}+\widehat{B}+\widehat{C}=180^0\)

=>\(x+60^0+40^0=180^0\)

=>\(x=180^0-100^0=80^0\)

Hình 2:

Xét ΔABD có \(\widehat{ADC}\) là góc ngoài tại đỉnh D

nên \(\widehat{ADC}=\widehat{ABD}+\widehat{BAD}=110^0\)

=>\(y=110^0\)

ΔDAC cân tại D

=>\(\widehat{DAC}=\widehat{DCA}=\dfrac{180^0-\widehat{ADC}}{2}\)

=>\(x=\dfrac{180^0-110^0}{2}=35^0\)

Hình 3:

Ta có: \(\widehat{CAB}+60^0=180^0\)

=>\(\widehat{CAB}=180^0-60^0=120^0\)

Xét ΔCAB có \(\widehat{CAB}+\widehat{ABC}+\widehat{ACB}=180^0\)

=>\(x+2x+120^0=180^0\)

=>\(3x=60^0\)

=>\(x=20^0\)

Hình 4:

Ta có: \(\widehat{ADC}+\widehat{ADB}=180^0\)

=>\(\widehat{ADB}=180^0-80^0=100^0\)

Xét ΔADB có

\(\widehat{ADB}+\widehat{ABD}+\widehat{BAD}=180^0\)

=>\(x+60^0+100^0=180^0\)

=>\(x=20^0\)

ta có: \(\widehat{ACD}+135^0=180^0\)

=>\(\widehat{ACD}=180^0-135^0=45^0\)

Xét ΔACD có \(\widehat{ACD}+\widehat{ADC}+\widehat{DAC}=180^0\)

=>\(y+80^0+45^0=180^0\)

=>\(y=55^0\)

Bài 8:

\(n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\)

\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

0,1--->0,15------>0,05---------->0,15

a. \(V_{H_2SO_4}=\dfrac{0,15}{1}=0,15\left(l\right)=150\left(ml\right)\)

b. \(V'=0,15.22,4=3,36\left(l\right)\)

c. \(CM_{Al_2\left(SO_4\right)_3}=\dfrac{0,05}{0,15}=\dfrac{1}{3}M\)

Bài 9:

\(n_{Fe}=\dfrac{2,8}{56}=0,2\left(mol\right)\)

\(Fe+2HCl\rightarrow FeCl_2+H_2\)

0,2-->0,4---->0,2------>0,2

a. \(V_{HCl}=\dfrac{0,4}{1}=0,4\left(l\right)=400\left(ml\right)\)

b.\(V_{H_2}=0,2.22,4=4,48\left(l\right)\)

c. \(CM_{FeCl_2}=\dfrac{0,2}{0,4}=0,5M\)

Bài 10:

\(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

\(Fe+2HCl\rightarrow FeCl_2+H_2\)

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

a. \(m=m_{Fe}=0,1.56=5,6\left(g\right)\)

b. \(V_{HCl}=\dfrac{0,2}{0,1}=2\left(l\right)=200\left(ml\right)\)

c.\(CM_{FeCl_2}=\dfrac{0,1}{2}=0,05M\)