Question

1/ a²- b²- 2(a - b).

2/x²+2x - 3.

Answer 1

1/ a² - b² - 2(a - b)

⇔ (a - b)(a + b) - 2(a - b)

⇔ (a - b)[a + b - 2]

2/ x² + 2x - 3

⇔ x² + 3x - x - 3

⇔ x(x + 3) - (x +3)

⇔ (x + 3)(x - 1)

Answer 2

1, \(a^2-b^2-2\left(a-b\right)\)

=(a\(^2\)-b\(^2\))-2(a-b)
=(a-b)(a+b)-2(a-b)
=(a-b)(a+b-2)

2, \(x^2+2x-3\)

=\(x^2\)+2x+1-4

=(\(x^2\)+2x+1)-4

=(x+1)\(^2\)-2\(^2\)

=(x+1-2)(x+1+2)

Answer 3

câu 2 đầu tiên mk thiếu \(x^2\) nhé