Problem
ALG-B1-M12-P018 Variant 5, Problem 2
#18
★★★★☆ Level 4 of 5
For which integers \(a\) does \(x^2+ax+20\) have integer roots?
The roots have product \(20\).
Sums of factor pairs: \(\pm21,\pm12,\pm9\). Thus \(a\in\{\pm21,\pm12,\pm9\}\).
Mock olympiad problem. Tags: vieta.