1) 16x^2-1 = (4x)^2- 1^2 = (4x+1)(4x-1) using (a^2-b^2)= (a+b)(a-b)
2) 3x^2-20x -32
= 3x^4-24x + 4x-32
= 3x(x-8)+4(x-8)
= (x-8)(3x+4)
3)
75x^3 - 27x = 3x(25x^2-9) = 3x(5x+3)(5x-3)
2006-10-12 16:48:21
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answer #1
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answered by Mein Hoon Na 7
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1) The difference of two squares, a^2-b^2, has the factorization (a+b)(a-b). In this case, a^2 = 16x^2, and b^2 = 1, so a=4x and b=1.
2) Look for a factorization of the form
(3x+a)(x+b)
where a+3b=-20 and ab=-32. One of a and b should be positive and the other negative, since their product is negative. Try factors of 32, such as 4 and 8. You find that a=4 and b=-8.
3) Factor out a 3x, and you get 3x(25x^2 - 9). The 25x^2 - 9 part is the difference of two squares, so you apply the same technique as in problem 1.
2006-10-12 23:49:46
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answer #2
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answered by James L 5
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#1. (16x^2-1) is a square minus a square, comes out to:
(4x-1)(4x+1)
#2. (3x^2-20x-32) equatratic equation form, comes out to:
(3x+4)(x-8)
#3. (75x^3-27x) pull out a GCF, then it is a square minus a square:
3x(25x^2-9) => 3x(5x+3)(5x-3)
2006-10-13 01:30:04
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answer #3
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answered by honest abe 4
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#1. 16x^2 - 1
= (4x - 1)(4x + 1)
#2. 3x^2 - 20x - 32
= (3x + 4)(x - 8)
#3. 75x^3-27x
= 3x (25x^2 - 9)
= 3x (5x - 3)(5x + 3)
2006-10-12 23:59:51
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answer #4
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answered by ideaquest 7
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#1. 16x^2 - 1 = (4x+1)(4x - 1)
#2. 3x^2 - 20x - 32
= 3x^2 + 4x - 24x - 32
= 3x(x - 8) + 4(x - 8)
= (3x + 4) (x - 8)
#3. 75x^3 - 27x
= 3x(25x^2 - 9)
= 3x(5x - 3)(5x + 3)
2006-10-12 23:50:35
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answer #5
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answered by rouhi a 1
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1) 16x^2-1=(4x+1)(4x-1)
2) 3x^2-20-32=(3x+4)(x-8)
3) 75x^3-27x=. 3x(25x^2-9)=>3x(5x+3)(5x-3)
2006-10-13 01:55:23
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answer #6
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answered by Anonymous
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1) (4x + 1)(4x -1)
2) (3x + 4)(x - 8)
3)3x(5x + 3)(5x - 3)
2006-10-13 00:04:03
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answer #7
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answered by harsh_bkk 3
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1) (4x-1)(4x+1)
2) (3x+4)(x-8)
2006-10-12 23:48:43
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answer #8
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answered by Al J 4
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