Question

Viết tổng sau thành tích :(x-y)^3-1-3(x-y)(x-y-1)

 

Answer 1

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

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

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

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

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

= \(^{\left(x-y-1\right)^3}\)

T*ck mình nha. Suy nghĩ bài này cực lắm đó!

Answer 2

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

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

= (x-y-1) [(x-y)^2 - 2(x-y)+1]

= (x-y-1)(x-y-1)^2

=(x-y-1)^3