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python - Solving Quadratic Equation

My program doesn't seem to give me the right solutions. Sometimes it does, sometimes it doesn't. I can't find my error. Any Suggestions?

import math

a,b,c = input("Enter the coefficients of a, b and c separated by commas: ")

d = b**2-4*a*c # discriminant

if d < 0:
    print "This equation has no real solution"
elif d == 0:
    x = (-b+math.sqrt(b**2-4*a*c))/2*a
    print "This equation has one solutions: ", x
else:
    x1 = (-b+math.sqrt(b**2-4*a*c))/2*a
    x2 = (-b-math.sqrt(b**2-4*a*c))/2*a
    print "This equation has two solutions: ", x1, " and", x2
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This line is causing problems:

(-b+math.sqrt(b**2-4*a*c))/2*a

x/2*a is interpreted as (x/2)*a. You need more parentheses:

(-b + math.sqrt(b**2 - 4*a*c)) / (2 * a)

Also, if you're already storing d, why not use it?

x = (-b + math.sqrt(d)) / (2 * a)

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