中等MATH-ALGE-002
Solve x^2 − 5x + 6 = 0.
A. x = −2 or x = −3
B. x = 2 or x = −3
C. x = −2 or x = 3
D. x = 2 or x = 3✓ 答案
解說
(x − 2)(x − 3) = 0, so x = 2 or x = 3. The other options flip one or both signs. Both roots are positive because the constant term is positive and the middle term is negative.