# algebra

posted by
**Rose** on
.

Please can someone help me with these?

factoring 2x^2+5x-3

and 3x^2-15x+12

Thanks in advance!!!

well rose. you nedd to distrubte the first one or find the gcf but there anit one, the second one do the same thing. for further questions just ask.

How can I do the same thing when you are saying there is nothing I can do for the first one?

On the first:

2x^2+5x-3

(2x-1)(x+3)

Does that help?

How do you know it is -1 and 3? I know -1 times 3 equals -3, but what does that have to do with 5? Is it because the 3 is half of 6 and 6 plus -1 equals 5?

simplify using identity

(a+b)3=a3+b3+3ab(a+b)

(5xy+6ab)3

2x^2+5x-3

OK, to start, split it up, like this:

( )( )

then, split up the 2x^2, like this:

(2x )(x )

The - sign in front of the 3 means you have to subtract to make 5.

Now, what are the factors of 3? 1 and 3, or 3 and 1... it doesn't matter. What you're trying to accomplish is to make 5. So far, the problem could look like this:

(2x 3)(x 1) or this: (2x 1)(x 3)

(we'll figure out the signs in a minute.)Now it's time to FOIL:

_____ _____ _____ ____

first outer inner last

Right now, we'll concentrate on the outer and inner. the first example would look like this:

+2x and the 2nd: +6x

+3x -1x

---- ----

+5x +5x

Can you see how the second one is right? +6x-1x=5x

The answer is (2x-1)(x+3)if you have any more questions, well, just ask!