x squared plus 3x minus 54=0
please help
2006-12-12 06:53:39 · 9 answers · asked by Marian H 1 in Science & Mathematics ➔ Mathematics
Xsquared + 3X = 54
x(x+3) = 54
6(6+3) = 54
X = 6
2006-12-12 06:56:24 · answer #1 · answered by Anonymous · 1⤊ 2⤋
i will answer this quadratic equations in 2 ways..
1. factoring
(x+9) (x-6) = 0
(x+9)=0 ; (x-6) = 0 (equating to 0)
x = -9 ; x = 6
2. Completing the square
x^2 + 3x = 54
X^2 + 3x + (9/4) = 54 + (9/4)
[x+ (3/2)]^2 = 225/4
[x+ (3/2)]^2 = (15/2)^2
x+3/2 = +15/2....or.. -15/2
x = 15/2 - 3/2........ x = -15/2 - 3/2
= 12/2.......................= -18/2
= 6............................= -9
that's the only help that i can give to you... :-)
2006-12-12 09:08:55 · answer #2 · answered by racz_jay25 2 · 0⤊ 0⤋
x^2-3x-54=0
(x-9)(x+6)=0
x=9 x=-6
2006-12-12 07:09:59 · answer #3 · answered by Anonymous · 0⤊ 0⤋
x²+3x-54=0
3² - 4.1.-54
9 + 216 = 225
x = (-3 +/-15) : 2
x '= (-3 + 15) : 2 = 6
x" = (-3 -15) : 2 = -9
Solution: {x E R | x = 6 or x = -9}
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2006-12-12 06:59:24 · answer #4 · answered by aeiou 7 · 0⤊ 1⤋
x^2+9x-6x-54=0
x(x+9)-6(x+9)=0
(x+9)(x-6)=0
x+9=0 or x=-9
and x-6=0 or x=6
thesolutio set is {6,-9}
2006-12-12 06:58:58 · answer #5 · answered by raj 7 · 1⤊ 0⤋
x²+3x-54=0
(x+9)(x-6) = 0
x' = -9 ... or .... x'' = 6
₢
2006-12-12 07:00:35 · answer #6 · answered by Luiz S 7 · 1⤊ 0⤋
I sware I took Pre Calculas in Highschool and graduated this January, honestly we never use what we have learned, God I miss those algebra days. well o well yeah I think those guys are right I can't remember anything
2006-12-12 07:07:02 · answer #7 · answered by eclipsefreak 4 · 0⤊ 0⤋
(x-6)(x+9) = 0
x = 6, -9
2006-12-12 06:56:08 · answer #8 · answered by jacinablackbox 4 · 2⤊ 0⤋
ohhh, parabola... neat.
2006-12-12 07:00:50 · answer #9 · answered by GuitarJammer 5 · 0⤊ 3⤋