Question

Phân tích đa thức Thành nhân tử
a) x² - y² - 2x - 2y
b) xy + y2
c) x² + 4xy + 4y² - 25
 

Answer 1

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

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

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

Answer 2

b) xy+y² = y ( x + y )

c) \(=\left(x^2+4xy+4y^2\right)-25\)

\(=\left(x+2y\right)^2-5^2\)

\(=\left(x+2y+5\right)\left(x+2y-5\right)\)