SOLUTION: S solve the quadratic equation by completing the square 3r^2+2r-2=0

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Question 723561: S solve the quadratic equation by completing the square 3r^2+2r-2=0
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
3r%5E2%2B2r-2=0+

/3
r%5E2%2B%282%2F3%29r-%282%2F3%29=0

r%5E2%2B%282%2F3%29r=%282%2F3%29
third term = (1/2 co efficient of middle term)^2

=((1/2) (2/3))^2
=1/9
r%5E2%2B%282%2F3%29r%2B%281%2F9%29+=%282%2F3%29%2B%281%2F9%29

r%2B%281%2F3%29%29%5E2=%287%2F9%29
Take square root
r+(1/3) = +-sqrt(7)/3
r= (-1+sqrt(7))/3
OR
r=(-1-sqrt(7))/3