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vee123
Jan 30, 2012, 01:16 PM
-16x2-48x-36

I keep getting (4x 8x 6)(-4x-8-6)

vee123
Jan 30, 2012, 01:18 PM
81m4-16

Is it prime?

vee123
Jan 30, 2012, 01:19 PM
4w2-256

I got (2w-16)(2w 16)

ebaines
Jan 30, 2012, 01:45 PM
-16x2-48x-36

i keep getting (4x 8x 6)(-4x-8-6)

Startig with:


-16x^2-48x-38


you can divide through by -4:


-4(4x^2+12x+9)


Now note that the factors of 4 are either 1 & 4 or 2 & 2, and factors of 9 are either 1 & 9 or 3 & 3. One set of combinations of these factors add to 12. Post back if you're still having trouble - show us what you tried and we'll help you along.

ebaines
Jan 30, 2012, 01:49 PM
4w2-256

i got (2w-16)(2w 16)

If you mean 4w^2 -256, and your answer is (2w-16)(2w+16) then yes, that's it. It's a difference of two squares.

Please note: if you copy and paste equations from other applications they don't turn out correctly, and so please type out the equations. Also, it is customary to use the carat sybol "^" to signify a power. Thus w^2 means "w squared."

ebaines
Jan 30, 2012, 01:49 PM
81m4-16

is it prime?

81m^4-16 looks like a diference of two squares to me.