How do the zeros change when you:
1. Change c from negative to positive, keeping a = 1 and b = 0 ?
2. Change a from positive to negative, keeping b = 0 and c = -1 ?
3. Change b from negative to positive, keeping a = 1 and c = 1 ?
4. How many real number solutions has the equation -0,53 x2 - 1,86 x - 1,37 = 0 ?
one
two
no real solutions