Factor 12x^2 - 4x - 15?

2 ⤊

Factor 12x^2 - 4x - 15?

If anyone has hints on how to do this that would be awesome.

2007-09-29 09:41:54 · 3 answers · asked by ryan 3 in Science & Mathematics ➔ Mathematics

3 answers

12x^2 - 4x - 15
= (12 x- 1-sqrt(46) ) (x -1/12 + sqrt(46)/12 )

2007-10-03 08:50:12 · answer #1 · answered by Anonymous · 1⤊ 0⤋

12x^2 - 4x - 15 = (x- 1-sqrt(46) /12) (12x -1 + sqrt(46) )

2007-10-03 14:18:52 · answer #2 · answered by robert 6 · 1⤊ 0⤋

b^2-4ac = 16-4(12)(-15) = 736
736 is not a perfect square so roots are irrational.
736 = 16*46 so sqrt(736) = 4sqrt(46)
The roots are x = [4 +/- 4sqrt(46)]/48
x = 1/12 +/- 1/12 sqrt(46) = 1/12(1 +/-sqrt(46))
Factors are:
(x-(1+sqrt(46))/12)(x-(1-sqrt(46))/12)

2007-09-29 17:01:20 · answer #3 · answered by ironduke8159 7 · 0⤊ 0⤋