SOLUTION: Could I get a little help on this expression??? Solve for x. {{{x^2+4x+4=7}}} I can only get this far then i forget what i am supposed to do. {{{x^2+4x+4-7=0}}} {{{x^2+4x-3=0}}

Algebra ->  Rational-functions -> SOLUTION: Could I get a little help on this expression??? Solve for x. {{{x^2+4x+4=7}}} I can only get this far then i forget what i am supposed to do. {{{x^2+4x+4-7=0}}} {{{x^2+4x-3=0}}      Log On


   

Question 100444: Could I get a little help on this expression??? Solve for x.
x%5E2%2B4x%2B4=7
I can only get this far then i forget what i am supposed to do.
x%5E2%2B4x%2B4-7=0
x%5E2%2B4x-3=0
Now what am i supposed to do?
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2%2B4x-3=0
you now need the quadratic formula
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B4x%2B-3+=+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=%284%29%5E2-4%2A1%2A-3=28.

Discriminant d=28 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-4%2B-sqrt%28+28+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%284%29%2Bsqrt%28+28+%29%29%2F2%5C1+=+0.645751311064591
x%5B2%5D+=+%28-%284%29-sqrt%28+28+%29%29%2F2%5C1+=+-4.64575131106459

Quadratic expression 1x%5E2%2B4x%2B-3 can be factored:
1x%5E2%2B4x%2B-3+=+%28x-0.645751311064591%29%2A%28x--4.64575131106459%29
Again, the answer is: 0.645751311064591, -4.64575131106459. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B4%2Ax%2B-3+%29