x- 5/x = 4
multiplt through by x gives
x² -5 = 4x
rearange
x² - 4x - 5=0
factorise
(x - 5)( x + 1) = 0
either (x - 5) = 0 so x = 5
or (x + 1 ) = 0 so x = - 1
multiplt through by x gives
x² -5 = 4x
rearange
x² - 4x - 5=0
factorise
(x - 5)( x + 1) = 0
either (x - 5) = 0 so x = 5
or (x + 1 ) = 0 so x = - 1
-
Add 5/x to both sides:
x/1 = 4 + 5/x
Subtract 4 from both sides:
x - 4 = 5/x
Multiply both sides by x:
x(x - 4) = 5
Expand x(x - 4) = 5:
x^2 - 4x = 5
Subtract 5 from both sides:
x^2 - 4x - 5 = 0
Use the quadratic equation to solve for x, or factor:
(x - 5)(x + 1) = 0
Two numbers multiplied together equal zero only if at least one of those numbers equals zero.
(x - 5) = 0 or (x + 1) = 0
x = 5 or x = -1
The trick to problems like this one is to isolate u/x to one side of the equals sign, where u is some real number, and then you can multiply both sides by x to get a quadratic.
As long as you don't divide anything by zero, the algebra will work.
x/1 = 4 + 5/x
Subtract 4 from both sides:
x - 4 = 5/x
Multiply both sides by x:
x(x - 4) = 5
Expand x(x - 4) = 5:
x^2 - 4x = 5
Subtract 5 from both sides:
x^2 - 4x - 5 = 0
Use the quadratic equation to solve for x, or factor:
(x - 5)(x + 1) = 0
Two numbers multiplied together equal zero only if at least one of those numbers equals zero.
(x - 5) = 0 or (x + 1) = 0
x = 5 or x = -1
The trick to problems like this one is to isolate u/x to one side of the equals sign, where u is some real number, and then you can multiply both sides by x to get a quadratic.
As long as you don't divide anything by zero, the algebra will work.
-
x/1-5/x
x-5/x=4 mult whol equation x to get rid of fraction
x^2-5x=4x add 5x toboth sides
x^2=9x div by 9
x^2)/9=x
x-5/x=4 mult whol equation x to get rid of fraction
x^2-5x=4x add 5x toboth sides
x^2=9x div by 9
x^2)/9=x
-
x/1 - 5/x = 4
Get the LCD..
x^2 - 5/x = 4
[(x^2 - 5)/x = 4] x
x^2 - 5 = 4x
x^2 - 4x - 5 = 0
(x-5) (x+1) = 0
x = 5 ; x = -1
Get the LCD..
x^2 - 5/x = 4
[(x^2 - 5)/x = 4] x
x^2 - 5 = 4x
x^2 - 4x - 5 = 0
(x-5) (x+1) = 0
x = 5 ; x = -1