(X – 2Y)2 = A) X2 + 2XY + 4Y2 B) X2 – 4XY + 2Y2C) X2 – 4XY + 4Y D) X2...

câu 1 : - DE THI HKITOAN20112012
Toán DE THI HKITOAN20112012

Câu 1 : (x – 2y)

2

=

a) x

2

+ 2xy + 4y

2

b) x

2

– 4xy + 2y

2

c) x

2

– 4xy + 4y d) x

2

– 4xy + 4y

2