12 This matter to which you should pay attention is of great importance

13 The woman to whom you gave place on the bus lives next door to me

1->13 mình làm ở đây nhé

→https://hoc24.vn/cau-hoi/giup-to-vss-a.7543535789690

a) Gọi $n_{Mg} = x(mol) ; n_{Al} = y(mol) \Rightarrow 24x + 27y = 25,5(1)$

$n_{N_2} = \dfrac{5,6}{22,4} = 0,25(mol)$

Bảo toàn electron : $2n_{Mg} + 3n_{Al} = 10n_{N_2} \Rightarrow 2x + 3y = 0,25.10(2)$

Từ (1)(2) suy ra :  x = 0,5 ; y = 0,5

$m_{Mg} = 0,5.24 = 12(gam)$
$m_{Al} = 0,5.27 = 13,5(gam)$

b) $n_{Mg(OH)_2} = x = 0,5(mol) ; n_{Al(OH)_3} = y = 0,5(mol)$

$\Rightarrow m_{Kết\ tủa} = 0,5.58 + 0,5.78 = 68(gam)$

Tổng 4 số đầu là:

\(11,2\cdot4=44,8\)

Tổng 2 số còn lại là:

\(112,8-44,8=68\)

Trung bình cộng hai số còn lại là:

\(68:2=34\)

Đáp số: 34

1 Life in the country is not as good as life in the city

2 These room are cleaned every evening

3 Would you mind decorating the christmas tree

4 It's the first time I have talked to the headmaster

V

1 have ever met

2 worked

3 reading

4 are looking - seeing

5 was

VI

1A

2A

3D

4D

5B

IV/

1. is not as good as life in the city

2. are cleaned every evening

3. decorating the Christmas tree?

4. the first time I have (ever) talked to the headmaster

V/

1. have ever met

2. worked

3. reading

4. are looking - seeing

5. was

VI/

1a 2a 3d 4d 5b

Ét ô ét

Bạn tham khảo lời giải tại đây:

https://hoc24.vn/cau-hoi/giai-pt-sqrtx-2sqrt4-x2x2-5x-1.219493072549

\(32\) x \(47,8+320\) x \(0,1+3200\) x \(0,512\)

\(=32\) x (\(47,8+10\) x \(0,1+100\) x \(0,512\))

\(=32\) x [(\(47,8+\) (\(10\) x \(0,1\)) \(+\) (\(100\) x \(0,512\))

\(=32\) x (\(47,8+1+51,2\))

\(=38\) x \(100\)

\(=3800\)