2007-02-05 15:34:44 · 7 answers · asked by Shawn Z 1 in Science & Mathematics ➔ Mathematics
Look up the quadratic equation... you'll use it for a long time.
2007-02-05 15:48:41 · answer #1 · answered by Eric L 5 · 0⤊ 1⤋
x^2 - 8x - 20 = 0 can be factored
you need 2 numbers that multiply to -20 and add to -8, these would be -10 and 2
so
x^2 - 8x - 20 = 0
(x - 10)(x + 2) = 0
to solve for x,
x - 10 = 0
x = 10
x + 2 = 0
x = -2
2007-02-05 23:39:42 · answer #2 · answered by Anonymous · 0⤊ 1⤋
I assume you need to factor the expression, correct?
First: multiply the 1st & 3rd coefficient to get "-20." Find two numbers that give you "-2" when multiplied & "-8" (2nd/middle coefficient) when added/subtracted. The numbers are (-10 & 2).
Sec: rewrite the expression with the new middle coefficients...
(x^2 - 10x) + (2x - 20)
Third: factor both sets....
x(x - 10) + 2(x - 10)
= (x -10)(x+2)
2007-02-06 00:18:23 · answer #3 · answered by ♪♥Annie♥♪ 6 · 0⤊ 0⤋
Factored form: (x + 2)(x - 10)
2007-02-05 23:39:56 · answer #4 · answered by S. B. 6 · 0⤊ 1⤋
are u trying to factor it??
cause if you are..it is (x-10)(x+2)
2007-02-05 23:39:23 · answer #5 · answered by Mickey mouse 1 · 1⤊ 1⤋
x^2-10x+2x-20
x(x-10)+2(x-10)
(x-10)(x+2)
2007-02-05 23:39:01 · answer #6 · answered by Anonymous · 1⤊ 0⤋
you better start getting used to this, I had this in college algebra.
2007-02-05 23:43:16 · answer #7 · answered by chazzer 5 · 0⤊ 1⤋