Question

bài 1 : phân tích các đa thức sau thành nhân tử

a) x³-1/16x

b) (3x + 1 ) ² -(x+2)²

c) 4xy-x²-4y²+16

d) 3x²+6x-3y²+3

Answer 1

b, \(\left(3x+1\right)^2-\left(x+2\right)^2\)

\(=\left(3x+1-x-2\right)\left(3x+1+x+2\right)\)

\(=\left(2x-1\right)\left(4x+3\right)\)

c, \(4xy-x^2-4y^2+16\)

\(=-\left(x^2-4xy+4y^2-16\right)\)

\(=-\left[\left(x-2y\right)^2-16\right]\)

\(=16-\left(x-2y\right)^2\)

\(=\left(4-x+2y\right)\left(4+x-2y\right)\)

Answer 2

\(d,3x^2+6x-3y^2+3\)

\(=3\left(x^2+2x+1-y^2\right)\)

\(=3\left[\left(x+1\right)^2-y^2\right]=3\left(x-y+1\right)\left(x+y+1\right)\)