Question

Solve the following quadratic equation by completing the square, showing ALL work: 2x^2 + 12x – 4 = 0

Answer 1

Divide thru by 2 in order to have a coefficient of 1 for the X^2. this results in:
x^2 + 6x -2 = 0
Now take 1/2 of the coefficient of the x term 6 getting three and square that getting 9 now add that to both sides getting:
x^2 +6x +9 - 4=9, now it is down hill the rest of the way just algebra.
(X+3)^2=13 Take the square root of both sides getting:
x+3=sqrt 13
\[x=-3\pm \sqrt{13}\] That is all there is to it.