Question

利用分解因式的分组分解法计算：ab+a+b+1；b^2+c^2-a^2+2ab

Answer 1

1.ab+a+b+1

= a(b + 1) + (b + 1)

= (a + 1)(b + 1)

2.b² + a² - c² + 2ab ---------估计你搞错了

= b² + a² + 2ab - c²

=(a + b)² - c²

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