2x²+10x-5=0, a=a, b=10, c=-5.
x = [-10±√(100+40)]/4 =
(√140=11.832 approximately)x=0.458 and -5.458
(2) For -6x² -x - 1/3=0, the equation can be rewritten as -18x² -3x-1=0
or 18x² +3x+1=0.
x = [-3±√ (9-72)]/36. The roots are not real as we got square root of an imaginary number.
When the discriminant, i.e. b²-4ac<0, the roots are imaginary.
In this case, the discriminant is equal to -63.
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