SOLUTION: I need to know how to start to solve this equation. 1/(x-1) + 1/2 = 2/(x^2-1)

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Question 638540: I need to know how to start to solve this equation.
1/(x-1) + 1/2 = 2/(x^2-1)

Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
Notice that:
(x^2-1)
is a "difference of squares"
(x^2-1^2)
we can factor as:
(x-1)(x+1)
.
So, we can rewrite your original equation:
1/(x-1) + 1/2 = 2/(x^2-1)
as:
1/(x-1) + 1/2 = 2/[(x-1)(x+1)]
multiply both sides by 2:
2/(x-1) + 1 = 4/[(x-1)(x+1)]
Now, we multiply both sides by (x-1)(x+1) to get:
2(x+1) + (x-1)(x+1) = 4
2x+2 + x^2-1 = 4
x^2+2x-1 = 4
x^2+2x-5 = 0
applying "quadratic formula" to get
x = {1.45, -3.45}
.
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B2x%2B-5+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%282%29%5E2-4%2A1%2A-5=24.

Discriminant d=24 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-2%2B-sqrt%28+24+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%282%29%2Bsqrt%28+24+%29%29%2F2%5C1+=+1.44948974278318
x%5B2%5D+=+%28-%282%29-sqrt%28+24+%29%29%2F2%5C1+=+-3.44948974278318

Quadratic expression 1x%5E2%2B2x%2B-5 can be factored:
1x%5E2%2B2x%2B-5+=+1%28x-1.44948974278318%29%2A%28x--3.44948974278318%29
Again, the answer is: 1.44948974278318, -3.44948974278318. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B2%2Ax%2B-5+%29