Bài 2 :
\(4x^2+4xy+y^2=\left(2x+y\right)^2\)
\(9m^2+n^2-6mn=\left(3m-n\right)^2\)
\(16a^2+25b^2+40ab=\left(4a+5b\right)^2\)
\(x^2-x+\dfrac{1}{4}=x^2-2.\dfrac{1}{2}+\dfrac{1}{4}=\left(x-\dfrac{1}{2}\right)^2\)
Bài 1:
a, ( 3 + xy2)2 = 32 + 2. 3. xy2 + (xy2)2 = 9+ 6xy2 + x2y4.
b, (10- 2m2n) = 102 - 2.10.2m2n + (2m2n)2 = 100 - 40m2n + 4m4n
c, ( a - b2)(a+b2) = bạn xem lại đề câu này nhé!
Bài 2:
a, 4x2 + 4xy + y2 = (2x)2 + 2. 2x. y + y2 = ( 2x + y)2
b, 9m2 + n2 - 6mn = ( 3m)2 - 2. 3m. n + n2 = ( 3m - n)2
c,16a2 + 25b2 +40ab = (4a)2 + 2. 4a. 5b + (5b)2 = ( 4a + 5b) 2
d, x2 - x +1/4 = x2 - 2. 1/2. x +(1/2)2 = (x - 1/2)2
