Question

1)3a²+6ab+3b²-12c²

2)a²+2ab+b²-ac-bc

3)x³-x²-x+1

Answer 1

b) a² + 2ab + b² - ac - bc

= ( a + b)² - c (a + b)

= ( a + b).( a + b - c )

c) x³ - x² - x + 1

= x² .(x - 1) - ( x - 1)

= ( x- 1).( x² - 1)

= ( x-1).(x-1).(x+1)

Answer 2

1)\(3a^2+6ab+3b^2-12c^2\)

\(=3\left(a^2+2ab+b^2-4c^2\right)\)

\(=3\left[\left(a^2+2ab+b^2\right)-4c^2\right]\)

\(=3\left[\left(a+b\right)^2-\left(2c\right)^2\right]\)

\(=3\left(a+b-2c\right)\left(a+b+2c\right)\)

Answer 3

Câu a) tớ cứ thắc mắc cái chỗ - 12c² nó ko ghép cặp vs cái nào hết Hình như đề sai