SOLUTION: Solve by using quadratic formula: x^2+4x+2=0 This is what I have, not sure if correct? x=-4+-square root 4^2-4(1)(2) divided by 2 x=-4+-square root 2 divided by 2 x=2

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Solve by using quadratic formula: x^2+4x+2=0 This is what I have, not sure if correct? x=-4+-square root 4^2-4(1)(2) divided by 2 x=-4+-square root 2 divided by 2 x=2       Log On


   

Question 109398: Solve by using quadratic formula:
x^2+4x+2=0
This is what I have, not sure if correct?
x=-4+-square root 4^2-4(1)(2) divided by 2
x=-4+-square root 2 divided by 2
x=2 x=-4
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: Quadratic Formula
Let's use the quadratic formula to solve for x:


Starting with the general quadratic


ax%5E2%2Bbx%2Bc=0


the general solution using the quadratic equation is:


x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29




So lets solve x%5E2%2B4%2Ax%2B2=0 ( notice a=1, b=4, and c=2)





x+=+%28-4+%2B-+sqrt%28+%284%29%5E2-4%2A1%2A2+%29%29%2F%282%2A1%29 Plug in a=1, b=4, and c=2




x+=+%28-4+%2B-+sqrt%28+16-4%2A1%2A2+%29%29%2F%282%2A1%29 Square 4 to get 16




x+=+%28-4+%2B-+sqrt%28+16%2B-8+%29%29%2F%282%2A1%29 Multiply -4%2A2%2A1 to get -8




x+=+%28-4+%2B-+sqrt%28+8+%29%29%2F%282%2A1%29 Combine like terms in the radicand (everything under the square root)




x+=+%28-4+%2B-+2%2Asqrt%282%29%29%2F%282%2A1%29 Simplify the square root (note: If you need help with simplifying the square root, check out this solver)




x+=+%28-4+%2B-+2%2Asqrt%282%29%29%2F2 Multiply 2 and 1 to get 2


So now the expression breaks down into two parts


x+=+%28-4+%2B+2%2Asqrt%282%29%29%2F2 or x+=+%28-4+-+2%2Asqrt%282%29%29%2F2



Now break up the fraction



x=-4%2F2%2B2%2Asqrt%282%29%2F2 or x=-4%2F2-2%2Asqrt%282%29%2F2



Simplify



x=-2%2Bsqrt%282%29 or x=-2-sqrt%282%29



So the solutions are:

x=-2%2Bsqrt%282%29 or x=-2-sqrt%282%29