SOLUTION: (2x-3)(x+1)=-1

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Question 1081450: (2x-3)(x+1)=-1
Found 2 solutions by Alan3354, MathLover1:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
(2x-3)(x+1)=-1
----
2x^2 - x - 3 = -1
2x^2 - x - 2 = 0
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 2x%5E2%2B-1x%2B-2+=+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=%28-1%29%5E2-4%2A2%2A-2=17.

Discriminant d=17 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--1%2B-sqrt%28+17+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-1%29%2Bsqrt%28+17+%29%29%2F2%5C2+=+1.28077640640442
x%5B2%5D+=+%28-%28-1%29-sqrt%28+17+%29%29%2F2%5C2+=+-0.780776406404415

Quadratic expression 2x%5E2%2B-1x%2B-2 can be factored:
2x%5E2%2B-1x%2B-2+=+%28x-1.28077640640442%29%2A%28x--0.780776406404415%29
Again, the answer is: 1.28077640640442, -0.780776406404415. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B-1%2Ax%2B-2+%29

Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

%282x-3%29%28x%2B1%29=-1
2x%5E2-3x%2B2x-3=-1
2x%5E2-x-3%2B1=0
2x%5E2-x-2=0
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-%28-1%29+%2B-+sqrt%28+%28-1%29%5E2-4%2A2%2A%28-2%29+%29%29%2F%282%2A2%29+
x+=+%281+%2B-+sqrt%28+1%2B16+%29%29%2F4+
x+=+%281+%2B-+sqrt%28+17+%29%29%2F4+
exact solutions:
x+=+%281+%2B+sqrt%28+17+%29%29%2F4+ or
x+=+%281+-+sqrt%28+17+%29%29%2F4+
approximately:
x+=1.28 or x+=-0.78