`a)x^2+4x+4=x^2+2.x.2+2^2=(x+2)^2->` HĐT số `1`
`b)16x^2+1-8x=(4x)^2-2.4x.1+1^2=(4x-1)^2->` HĐT số `2`
`c)9x^2+6xy+y^2=(3x)^2+2.3x.y+y^2=(3x+y)^2->` HĐT số `1`
a: \(=\left(x+2\right)^2\)
b: \(=\left(4x-1\right)^2\)
c: \(=\left(3x+y\right)^2\)
`a, = (x+2)^2`
`b, = (4x - 1)^2`
`c, = (3x+y)^2`
a, \(x^2+4x+4=\left(x+2\right)^2\)
b, 16x^2 + 1 - 8x = ( 4x - 1 )^2
c, 9x^2 + 6xy + y^2 =( 3x + y )^2