2x^2-x-15=0 by the zero-factor property.?

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2x^2-x-15=0 by the zero-factor property.?

2007-09-04 06:43:37 · 3 answers · asked by bealsey1 2 in Science & Mathematics ➔ Mathematics

3 answers

(2x + 5) (x - 3) = 0
x = - 5 / 2 , x = 3

2007-09-08 06:09:07 · answer #1 · answered by Como 7 · 0⤊ 0⤋

2x^2 - x - 15
= (2x + 5)(x - 3)
= 0

Therefore, x = -5/2 or x = 3

2007-09-04 14:00:46 · answer #2 · answered by Bananaman 5 · 0⤊ 0⤋

ax^2+bx+c=0
x=[-b+-sqrt(b^2-4ac)]/2a
a=2 b=-1 c=-15
x=[1+sqrt(1+120)]/4
=[1+11]/4=3 (one solution)
x=[1-sqrt(121)]/4=-10/4=-5/2=-2.5 (second solution)

2007-09-04 13:57:32 · answer #3 · answered by cidyah 7 · 0⤊ 0⤋