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April 28th, 2008, 04:25 PM
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| |  factoring help
Hello people! I need help with two math problems. They ask me to factor: 25a to the fourth - 14a squared b to the fourth + b to the eigth.
factor: 3a to the fourth + 48b to the fourth - 36a squared b squared.
I cannot figure out either one. With the first I need a number squared that equals 24, which is impossible of course, and the second I figured out I need a number squared that equals 20 which is also impossible (I figured that out with my own made-up equation.) Will someone show me how to solve these problems? I have tryed ever thing I can think of. Thank-you. |
April 28th, 2008, 04:59 PM
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Quote:
Originally Posted by jesuslover  Hello people! I need help with two math problems. They ask me to factor: 25a to the fourth - 14a squared b to the fourth + b to the eigth.
factor: 3a to the fourth + 48b to the fourth - 36a squared b squared.
I cannot figure out either one. With the first I need a number squared that equals 24, which is impossible of course, and the second I figured out I need a number squared that equals 20 which is also impossible (I figured that out with my own made-up equation.) Will someone show me how to solve these problems? I have tryed ever thing I can think of. Thank-you. | 
Factor out a^2 to get  |
April 29th, 2008, 10:41 AM
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HI! HERE ARE THE SOLUTIONS:
1> 25a to the fourth - 14 a squared b to the fourth + b to the eight
= 25 a to the fourth - 10 a squared b to the fourth + b to the eight -
4 a squared b to the fourth
= square of (5 a squared -b to the fourth) - square of (2ab squared )
= ( 5 a2 + 2ab2 - b4)(5a2 - 2ab2 - b4)
2> 3a4 + 48b4 - 36a2b2
= 3(a4 - 12a2b2 + 16b4)
= 3 { a4 -8a2b2 + 16b4 - 4a2b2}
= 3 { ( a2-4b2)2 - (2ab)2
= 3 { (a2 -2ab -4b2)(a2 +2ab - 4b2)
= 3 (a2-2ab -4b2)(a2 + 2ab - 4b2)
got it!!! |
April 30th, 2008, 10:39 AM
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Hi! Thank-you for your help, but I decided to give it one last try last night and was able to figure it out. I'm sorry I bothered you guys. I really was stuck at the time. I need to learn to look back at the book when I'm stuck. or at least more closely. I'm sorry. |
April 30th, 2008, 10:46 AM
|  | Bar0n | | Join Date: Apr 2007 Location: South African Republic
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Quote:
Originally Posted by jesuslover Hi! Thank-you for your help, but I decided to give it one last try last night and was able to figure it out. I'm sorry I bothered you guys. I really was stuck at the time. I need to learn to look back at the book when I'm stuck. or at least more closely. I'm sorry. | No problem... We are here to help and for someone as nice as you, we are more than happy to help again 
__________________ If you need more than 3 levels of indentation, you're screwed anyway, and should fix your program. - Linus Torvalds
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