Question 80076
What values of b in the following equations will give one or more real number solutions?
Look at b^2-4ac for each equation: 
a). 3x^2+bx-3=0
b^2-4ac
=b^2-4*3*-3
=b^2+36
This expression will be non-negative for all values of "b".
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b). 5x^2+bx+1=0
b^2-4ac
=b^2-4*5*1
=b^2-20
This expression will be non-negative for all b>=2sqrt5 or less than -2sqrt5
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c). -3x^2+bx-3=0 
b^2-4ac
=b^2-4*-3*-3
=b^2-36
This expression be non-negative for all b >=6 or <= than -6
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what is a rule for judging if an equation has solutions by looking at it in standard form?
b^2>=4ac
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Cheers,
Stan H.