Alegebraic equation halp
Name:
Anonymous
2008-10-15 21:30
I'm stuck on one particular problem:
n - 2/n = 23/5
Now I cancel out the denominators by 5n:
5n^2 - 10 = 23n
Then go further:
5n^2 - 23n - 10 = 0
I'm stuck now as I can't find a way to factor this out as. I'm not asking for anyone to solve it, but just where I need to go to solve it.
Name:
4tran
2008-10-15 21:53
(5n+2)(n-5)=0
If you can't factor, then quadratic equation/complete the square.
Name:
Anonymous
2008-10-15 21:56
(x-5 )( 5x+2 )
x-5 5x+2=0 = -2/5
(x=5)(x=-2/5)
i wish i could explain how i did it, i backward foiled it in my head .
or basically multiply (5)(-10) -50 and the coefficient of x= -23 find the number who's product equals to -50 and equals the sum to -23
those numbers are 2 and -25
so now we have these number take out 5x and put in 5x^2+2x-25x-10=0
now factor 5x^2+2x and 25x-10
5x+2=0 x=5
sorry im bad at explaining
Name:
Anonymous
2008-10-15 22:06
Thanks guys.
Name:
Anonymous
2008-10-15 23:17
ax^2+bx+c
5x^2 - 23x - 10
5x^2 - 25x + 2x - 10
5x^2 - 25x | + 2x - 10
5x(x-5) | + 2x - 10
5x(x-5) | + 2(x-5)
(x-5)(5x+2)
(x-5)(5x+2) = 0
x = 5, 5/2
Sorry if I didn't explain it well enough
The breakers ( | ) are simply for visual management, they are not actually part of the equation
Name:
Anonymous
2008-10-15 23:18
Samefag as last, meant to put x=5, -2/5
Name:
Anonymous
2008-10-17 5:44
use the fuckin' quadratic formula.