11 D

12 A

13 C

14 C

15 A

Câu 11 D

Câu 12 A

Câu 13 C

Câu 14 C

Câu 15 A

D

A

C

C

A 

Chúc bn hc tốt ^^ 

i) Ta có: \(9^8\cdot2^8-\left(18^4-1\right)\left(18^4+1\right)\)

\(=18^8-18^8+1\)

=1

Bài 4: 

a) Ta có: \(\left(x+3\right)^2-\left(x-3\right)^2-12x\)

\(=x^2+6x+9-x^2+6x-9-12x\)

=0

b) Ta có: \(\left(x-2\right)^2-\left(x-3\right)\left(x-1\right)\)

\(=x^2-4x+4-x^2+4x-3\)

=1

c) Ta có: \(\left(x-3\right)\left(x^2+3x+9\right)-x^3\)

\(=x^3-27-x^3\)

=-27

d) Ta có: \(\left(3x+2\right)\left(9x^2-6x+4\right)-9x\left(3x^2+1\right)+9x\)

\(=27x^3+8-27x^3-9x+9x\)

=8

1Chicken is my favourite food

=My favourite food is chicken

2We have a vacation last three mounth

=we have 3-mounth vacation

lấy vế từ sau tobe đảo lên trước rồi tới tobe cuối cùng là chữ đứng đầu thường là zậy

Ex1: I learn English because I want to travel around the world

->I learn English in order to/ so as to travel around the world

->i learn English so that I want to travel around the world

=> in orther to/ so as to + v(bare_inf)

Ex2: '' Please close the window'' she said:

->She asked me to close the window.

-> She told me to close the window.

................... ( còn nhiều )

lm hộ mik vs mn ơiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

e, \(=\dfrac{1}{2}x^6y^8-\dfrac{3}{2}x^6y^8=-x^6y^8\)

f, \(=-\dfrac{1}{2}xy^2\left(\dfrac{4}{9}x^4y^2\right)+\dfrac{5}{2}x^5y^4-\dfrac{1}{4}x^4y^2.xy^2=-\dfrac{2}{9}x^5y^4+\dfrac{5}{2}x^5y^4-\dfrac{1}{4}x^5y^4=\dfrac{89}{36}x^5y^4\)

g, \(=-\dfrac{5}{2}x^5y^2+\dfrac{3}{7}.8x^3\left(\dfrac{49}{4}x^2y^2\right)-x^5y^2=-\dfrac{7}{2}x^5y^2+42x^5y^2=\dfrac{77}{2}x^5y^2\)

help me!

a a c b a

đg thi ah ?

em chịu nhìn đx hoa cả mắt òi

môn j đấy

ghi rõ hộ đi

hok tốt !!

_Ko làm đc bài hử nhạt

thương ghê

tử tự????????????