MC數一條

2007-07-07 3:59 am

which of the following is a factor of 2(a-b)^2-a^2+b^2?
A) a-3b B)a-2b C)a+b .... show step only

回答 (2)

2007-07-07 4:16 am

✔ 最佳答案

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

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

=2a^2 - 4ab+2b^2 - a^2+b^2

=a^2 - 4ab+3b^2

=(a-b)(a - 3b)

so,answer is A

👍 0 👎 0

2007-07-07 5:05 am

2(a-b)^2-a^2+b^2
=2(a^2 - 2ab+b^2) - a^2+b^2
=2a^2 - 4ab+2b^2 - a^2+b^2
=a^2 - 4ab+3b^2
=(a-b)(a - 3b)

The answer is A

👍 0 👎 0