SOLUTION: I need some help with this problem. Solve by completing the square. 2x^2+8x+3=0

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Question 52341This question is from textbook Beginnning Algebra
: I need some help with this problem.
Solve by completing the square.
2x^2+8x+3=0
This question is from textbook Beginnning Algebra

Answer by sumanth18(2) About Me  (Show Source):
You can put this solution on YOUR website!
A typical quadratic equation is of the form :
+a%5E2%2Ax%2Bb%2Ax%2Bc+=0
SOlve by completing squares means to rearrange the given quadratic into the neat format demonstrated above.
To start this we first move the loose number to the other side ,which in our case is 3.
Therefore we have
+2%2Ax%5E2%2B+8%2Ax+=+-3+
Next we divide through by whatever is multiplied on the squared term,which in our case will be divided by 2.
Therefore we have the following +x%5E2%2B+4%2Ax+=+-3%2F2+
Next step, take half of the coefficient (don't forget the sign!) of the x-term, and square it. Add this square to both sides of the equation
Here the co-efficient of x term in our case is 4 .
Therefore when we take half of the co-efficient we get 2 and sign is '+'
SQuaring we get 4
adding to both sides we get,
+x%5E2%2B+4%2Ax+%2B+4++=+-3%2F2+%2B4++
Convert the left-hand side to squared form, and simplify the right-hand side
(Hint : This is where the sign that you kept track of earlier comes handy.)
+%28x%2B2%29%5E2++=+-3%2F2+%2B4++
Taking square root on both sides we get,
(x+2)= +- sqrt+%282.5%29
Therefore x = +- sqrt%282.5%29-2
Solve for x we get ,
x= -1.5811-2 and x= 1.5811-2
i.e x= -3.5811 and x=-0.4189