2007-10-19 07:58:08 · 10 answers · asked by tankwillmsg 1 in Science & Mathematics ➔ Mathematics
x^2 - 5 = 4x
x^2 - 4x -5 = 0
(x-5)(x+1)=0
x = 5 or -1
2007-10-19 08:02:26 · answer #1 · answered by norman 7 · 0⤊ 0⤋
,x - 5/x = 4 if this equation, is multiplied for x, then:
= x^2 - 5 = 4x
x^2 -4x -5 = 0 (x-5)(x+1)
x = 5
x = -1
2007-10-19 08:10:20 · answer #2 · answered by Eduardo (lalo) Leal 2 · 0⤊ 0⤋
x - 5/x = 4
x² - 5 = 4x
x² - 4x - 5 = 0
(x - 5)(x + 1) = 0
x = 5, -1
Be sure to check the solutions in the original equation
to be sure they don't cause the denominator to equal 0
and also to check your work.
5 - 5/5
= 5 - 1
= 4
-1 - 5/(-1)
= -1 + 5
= 4
2007-10-19 08:07:25 · answer #3 · answered by Marvin 4 · 0⤊ 0⤋
Firstly, multiply the equation by x ...
x^2 - 5 = 4x
Now subtract 4x from each side...
x^2 - 4x - 5 = 0
This factorises into (x - 5)(x + 1) = 0
giving either x = 5 or x = -1
2007-10-19 08:03:12 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Ans.
x^2-5-4x=0
x^2-4x-5=0
x^2+x-5x-5=0 x(x+1)-5(x+1)=0, (x-5)(x+1)=0
Ans. x=5
x= -1
2007-10-19 08:49:12 · answer #5 · answered by Sasi Kumar 4 · 0⤊ 0⤋
x² - 5 = 4x
x² - 4x - 5 = 0
(x - 5)(x + 1) = 0
x = 5 , x = - 1
2007-10-19 11:19:26 · answer #6 · answered by Como 7 · 1⤊ 0⤋
x - 5/x = 4
multiply throughout by x
x^2-5 =4x
x^2-4x-5 =0
x^2-5x+x-5 =0
x(x-5)+1(x-5)=0
(x+1)(x-5)=0
x=-1,5
2007-10-19 08:12:38 · answer #7 · answered by Siva 5 · 0⤊ 0⤋
x-5/x=4
x*x-(5/x)*x=4*x
x^2-5=4x
x^2-4x-5=0
(x-5)(x+1)=0
x=5 x=-1
2007-10-19 08:05:59 · answer #8 · answered by Anonymous · 0⤊ 0⤋
x-5/x=4
x^2-5=4x (mult. all terms by x)
x^2-4x-5=0
(x-5)(x+1)=0
For (x-5)(x+1) to equal zero, either x-5=0 or x+1=0
If x-5=0, x=5
If x+1=0, x=-1
2007-10-19 08:04:52 · answer #9 · answered by Grampedo 7 · 0⤊ 0⤋
x(x-5/x)=4x
x-5=4x
3x=-5
x=-5/3
2007-10-21 11:57:01 · answer #10 · answered by Anonymous · 0⤊ 0⤋