We'll notice that the product of the 2 ratios
x/(x+1)*(x+1)/x = 1.
If we'll square raise the product,
we'll obtain:
[x/(x+1)]^2*[(x+1)/x]^2 =
1
We'll substitute the ratio [x/(x+1)]^2 =
t
t = 1/[(x+1)/x]^2
We'll
re-write the equation:
t + 1/t =
17/4
4t^2 + 4 = 17t
We'll
subtract 17 t both sides:
4t^2 - 17t + 4 =
0
We'll apply the quadratic
formula:
t1 = [17 + sqrt(289 -
64)]/8
t1 = (17+15)/8
t1 =
32/8
t1 = 4
t2 =
(17-15)/8
t2 = 2/8
t2 =
1/4
Since t = [x/(x+1)]^2, both values for t have to be
positive and they are.
[x/(x+1)]^2 =
4
x/(x+1) = 2
x = 2x +
2
-x = 2
x =
-2
x/(x+1) =
-2
x = -2x - 2
3x =
-2
x =
-2/3
x/(x+1) =
1/2
2x = x+1
x =
1
x/(x+1) =
-1/2
2x = -x-1
3x =
-1
x =
-1/3
The roots of the equation
are: {-2 , -2/3 , -1/3 , 1}.
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