Question

Phân tích : \(\text{x^2 - 2xy + y^2 + 4x - 4y - 5}\)

Answer 1

Xin lỗi, chj làm lại nhé *(^o^)*

x² - 2xy + y² + 4x - 4y - 5

= (x - y)² + 4(x - y) - 5

Đặt x - y = t, ta có:

t² + 4t - 5

= t² - t + 5t - 5

= t(t - 1) + 5(t - 1)

= (t - 1)(t + 5)

= (x - y - 1)(x - y + 5)

Answer 2

\(x^2-2xy+y^2+4x-4y-5\)

\(=\left(x-y\right)^2+4\left(x-y\right)-5\)

Đặt x - y = t, ta có:

\(t^2+4t-5\)

\(=t^2+t-5t-5\)

\(=t\left(t+1\right)-5\left(t+1\right)\)

\(=\left(t+1\right)\left(t-5\right)\)

\(=\left(x-y+1\right)\left(x-y-5\right)\)