Answer:
0
Explanation:
For a quadratic of the form
ax² +bx +c = 0
The "discriminant" is the expression ...
b² -4ac
For this equation, we have a=1, b=5, c=7, so the discriminant is ...
5² -4·1·7 = -3
When the discriminant is negative there will be two distinct complex roots to the equation, and no real roots.
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When the discriminant is zero, there will be one real root with multiplicity 2; when it is positive, there will be two distinct real roots.