1,D

2,B

3,B

4,C

1,D

2,A

3,A

4,D

5,C

1 B

2 A

3 D

4 C

5 D

6 A

7 C

8 A

9 B

10 A

Trời trời giúp mình với mấy thần đồng tiếng anh ơi , mình sắp toang ròi 😢😢😢

1 eats => has eaten

2 buy => bought

3 took => take

4 ate => eat

5 and => so

6 so => as

7 photo => photography 

8 are, either => were, too

9 the puppets => puppets

10 take => takes

a: \(=\left(2a^2-3a^2-4a^2\right)+\left(-0.5a-2.5a+3a\right)+\left(5-4+7\right)=-5a^2+8\)

b: \(=\left(a^3-a^3\right)+\left(-2a^2-3a^2+4a^2\right)+\left(a+a-a\right)+\left(-5+4\right)=-a^2+a-1\)

c: \(=-b^4+3b^2-3b-1-b^3+1-3b^2+b^4-5+4b^3+5\)

\(=3b^3-3b\)

\(x^3+2x^2\left(4y-1\right)-4xy^2-9y^3-f\left(x\right)=-5x^3+8x^2y-4xy^2-9y^3\\ \Rightarrow\left(x^3+8x^2y+2x^2-4xy^2-9y^3\right)-f\left(x\right)=-5x^3+8x^2y-4xy^2-9y^3\\ \Rightarrow f\left(x\right)=x^3+8x^2y+2x^2-4xy^2-9y^3+5x^3-8x^2y+4xy^2+9y^3\\ \Rightarrow f\left(x\right)=6x^3+2x^2\)

Bài 2: 

a: =>168x+20=6x-21

=>162x=-41

hay x=-41/162

b: \(\Leftrightarrow2\left(3x-8\right)=3\left(5-x\right)\)

=>6x-16=15-3x

=>9x=31

hay x=31/9

c: \(\Leftrightarrow4\left(x^2+8x-20\right)-\left(x+4\right)\left(x+10\right)=3\left(x^2+2x-8\right)\)

\(\Leftrightarrow4x^2+32x-80-x^2-14x-40-3x^2-6x+24=0\)

=>12x-96=0

hay x=8