hjbjkrjeanjk ikbhnbalihbs 

cần gấp lắm ạ xin các bạn giúp đỡ . ___ .

Câu 1: 

0,9 x 218 x 2 + 0,18 x 4290 + 0,6 x 353 x 3

= 9/10 x 436 + 9/50 x 4290 + 6/10 x 1059

= 9 x 43,6 + 9 x 85,8 + 6 x 105,9

= 3 x 130,8 + 3 x 257,4 + 3 x 211,8

= 3 x ( 130,8 + 257,4 + 211,8 )

= 3 x 600 

= 1800

Câu 2: 

3/4 x X + 1/2 x X - 15 = 35

X x ( 3/4 + 1/2 ) - 15 = 35

X x ( 3/4 + 1/2 ) = 50

X x 5/4 = 50

X = 40

VẬy X = 40

1.  0.9x218x2+0.18x4290+0.6x353x3  

= 1.8x218+0.18x10x429+1.8x353

=1.8x218+1.8x429+1.8x353

= 1.8x( 218+429+353 )

= 1.8x1000

=1800

2. 

3/4 x X + 1/2 x X - 15 = 35

3/4 x X + 1/2 x X = 35+15

3/4 x X +1/2 x X = 50

X x ( 3/4 + 1/2 ) = 50 

X x 5/4 = 50 

X = 50 : 5/4

X =40

đù mik cx có 1 bài như này

Bài 5: 

CTPT: C_xH_yO

\(n_{CaCO_3}=\dfrac{40}{100}=0,4\left(mol\right)\)

PTHH: 2C_xH_yO + \(\dfrac{4x+y-2}{2}\)O₂ --t^o--> 2xCO₂ + yH₂O

              \(\dfrac{0,4}{x}\)<--\(\dfrac{0,4\left(4x+y-2\right)}{4x}\)<------0,4

             Ca(OH)₂ + CO₂ --> CaCO₃ + H₂O

                                0,4<-----0,4

=> \(M_{C_xH_yO}=\dfrac{7,4}{\dfrac{0,4}{x}}=18,5x\left(g/mol\right)\)

=> y + 16 = 6,5x (1)

Có \(n_{O_2}=\dfrac{19,2}{32}=0,6\left(mol\right)\)

=> \(\dfrac{0,4\left(4x+y-2\right)}{4x}=0,6\)

=> 0,8x = 0,4y - 0,8 (2)

(1)(2) => x = 4; y = 10

CTPT: C₄H₁₀O

    I know many festivals but the one I like the most is Tet. It is the most important festival in Vietnam. Tet is celebrated every year on January 1 of the lunar calendar. When Tet comes, we are 1 year old. Before Tet, family members will go to buy food, fruit, and flowers. And they also buy decorations and cherry blossom lines. People will decorate the house, and they will place the potted peach blossom tree in the right front position of the house. They also make banh chung, the traditional dish of our country. During Tet, everyone in the family will gather together and tell each other about the past years in order to enter a better New Year together. They will eat the same banh chung. After that, we will visit relatives and neighbors. And our children will receive lucky money. On New Year's Eve, everyone can watch the colorful fireworks in the sky together. I love Tet, every year I look forward to Tet, to see my loved ones again

II/ 

1. B (theo quy tắc phát âm s, es: ở đáp án A C D phần gạch chân phát âm là /s/, còn ở đáp án B phát âm là /z/)

2C 3D (2 câu này bạn tra từ điển để xem và nghe cách phát âm nha)

4. A (theo quy tắc phát âm ed, ở B C D phần gạch chân phát âm là /id/, còn ở đáp án A phát âm là /t/)

II

1 B

2 C

3 B

4 A

III

1 B

2 A

3 D

 ai có CT j ko ạ