SOLUTION: solve using quadratic formula r^2+3r-3=0

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Question 285245: solve using quadratic formula
r^2+3r-3=0
Answer by toidayma(44) About Me  (Show Source):
You can put this solution on YOUR website!
r%5E2+%2B+3r+-+3+=0 <-> r%5E2+%2B+%282%29%283%2F2%29%28r%29+%2B+%283%2F2%29%5E2+-+%283%2F2%29%5E2+-+3+=+0+ <-> %28r+%2B+3%2F2%29%5E2+=+45%2F4+=+%283sqrt%285%29%2F2%29%5E2+ <-> %28r+%2B+3%2F2%29+%2B-+%283%2Asqrt%285%29%29%2F2+=+0 <-> r+=+-3%2F2+%2B-+%283%2Asqrt%285%29%29%2F2 <-> r+=+-3%281%2B-sqrt%285%29%29%2F2
Note:
You know a%5E2+=+b%5E2 <-> a+%2B-b+=+0 right? It is also easy to prove: a%5E2+=+b%5E2 <-> a%5E2+-+b%5E2+=+0 <-> %28a-b%29%28a%2Bb%29+=+0, and that's it.