SOLUTION: i need help using the discriminant to find the number of unique real solutions of 3x^2+3x=21 Thanks.

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Question 1104098: i need help using the discriminant to find the number of unique real solutions of 3x^2+3x=21
Thanks.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
ax%5E2%2Bbx%2Bc=0
Discriminant is b%5E2-4ac.
SIGN of Discriminant   SOLUTIONS
Negative                 0
Zero                     1
Positive                 2


3x%5E2%2B3x=21
3x%5E2%2B3x-21=0
-
system%28a=3%2Cb=3%2Cc=-21%29

Make the substitutions, evaluate, and decide.