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smc

algebra senior

Problem

For how many ordered pairs of positive integers does neither nor have two distinct real solutions?
(A)
(B)
(C)
(D)
Solution
A quadratic equation does not have two distinct real solutions if and only if the discriminant is nonpositive. We conclude that: 1. Since does not have real solutions, we have 2. Since does not have real solutions, we have Squaring the first inequality, we get Multiplying the second inequality by we get Combining these results, we get We apply casework to the value of If then from which If then from which If then from which If then from which Together, there are ordered pairs namely and
Final answer
B