Question

Which of the following correctly shows the first step when factoring 5a^2b-5a^2c-5db+5dc by grouping?

1) 5a^2 (b-c)-5d(b-c)
2) 5a^2 (b+c) +5d(b+c)
3) 5a^2 (b+c) -5d(b+c)
4)5a^2 (b-c) +5d(b-c)

Answer 1

the answer is 1.

Explanation:

I got it right on my test.

Answer 2

Correct choice is 1)
`5a^2 (b-c)-5d(b-c)`.

Explanation:

Given expression is :
`5a^2b-5a^2c-5db+5dc`

Now we need to factor it by completing square to match the correct choice.

`5a^2b-5a^2c-5db+5dc`

Make two groups having first two terms and last two terms then find GCF of each.

`=5a^2(b-c)-5d(b-c)`

Hence correct choice is 1)
`5a^2 (b-c)-5d(b-c)`.