Trong các khai triển hằng đẳng thức sau, khai triển nào sai?

A.(A + B)^2=A^2+2AB+B^2 

B.(A + B)^3=A^2+2A^2B+2AB^2+B^3

C.(A - B)^2=A^2-2AB+B^2

D.(A - B)^2=A^3-3A^2B+3AB^2-B^3

kết quả của phép nhân 3x(x^2+2x-1) là:

A.3x^3+5x^2-3x

B.3x^2+6x^3-3x

C.3x^3-3x^2+6x

D.3x^3+6x^2-3x

Liệt kê tất cả các cụm đồng nghĩa trong bài :((

Put the correct verb forms. use 3rd type only

1. If my car…, I…. here at 8 o’clock. (not break down; be)

2. ... you ... if you had driven more slowly. (crash)

3. ... you ... harder at school last year if you... the teacher. (study; like)

4. ... you... me if i ... you? (helps; ask)

Make sentences in two ways.

ex: 1.my parents don't leave near here, so i don't see them at weekends.

if my parents lived near here, i would see them at weekends.

i would see them at weekends if they lived near here.

2. we won't play cards because Jane and Peter aren't here.

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3. we haven't got enough money so we won't by a new car.

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4. Fred aren't answer letters, so i don't write to him.

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5. I won't take your photo because i can't find my camera.

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6. I don't enjoy opera because i can't understand the words.

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