Which of the following is a factor of xy + 3y − 7x − 21?

5
x + 3
x2 − 3x + 9
All of the above

Question

Which of the following is a factor of xy + 3y − 7x − 21?

 5
 x + 3
 x2 − 3x + 9
 All of the above

princesssleelee · Answer

I think maybe, B

anonymous · Answer

You're right.

anonymous · Answer

ya, your right.

princesssleelee · Answer

Which is a factor of 20x2 + 40x + 15?

 4x + 1
 4x + 3
 2x + 3
 x + 2

princesssleelee · Answer

Im not sure on this one

anonymous · Answer

First, can you factor anything out of all three terms?

anonymous · Answer

First, divide everything by five.

anonymous · Answer

Sooo, you get 4^2+8x+3. Now factorize it.

princesssleelee · Answer

Im not quite sure how to do that

anonymous · Answer

Well you can't just get rid of the 5, you factor it out so you get
$$5(4x ^{2}+8x+3)$$

anonymous · Answer

Yes you can,

anonymous · Answer

No you can't. The two expressions would not be equivalent if you just got rid of it completely.

anonymous · Answer

When factorizing, the equation is always equal to 0. When you divide by five, you do 0/5 which is still zero.

anonymous · Answer

This is not an equation, it is an expression. It is not equal to zero.

princesssleelee · Answer

im thinking its 2x+3

anonymous · Answer

Factorize:
|dw:1450895838470:dw|
You look for the 2 multipuls of you x^2 and the last digit. Multiply them across then add them to see if it's the middle number.

anonymous · Answer

2x+3 is right. The full factorization would be 5(2x+1)(2x+3)

anonymous · Answer

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