Advanced Math practice question

Answer: A. 0

The discriminant is b² − 4ac = 4² − 4(1)(5) = 16 − 20 = −4. A negative discriminant means no real solutions. Check the discriminant before attempting to factor.

Why the other answers are wrong

B. 1

A quadratic has exactly one real solution only when the discriminant equals 0; here b²−4ac = 16−20 = −4, which is negative, not zero.

C. 2

Two real solutions require a positive discriminant, but 4²−4(1)(5) = −4. Not every quadratic crosses the x-axis — check the sign of the discriminant first.

D. Infinitely many

Infinitely many solutions happen only when an equation reduces to something always true, like 0 = 0. A quadratic with a nonzero leading coefficient can have at most 2 real solutions.

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