1966 AMC 12 Problem 30

Attempt Problem 30 of the 1966 AMC 12 below, then check your answer against the professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 1966 AMC 12 solutions, or check the answer key.

All problems are used with official legal permission of the Mathematical Association of America (MAA).

30.

If three of the roots of x4+ax2+bx+c=0x^4+ax^2+bx+c=0 are 1,1, 2,2, and 3,3, then the value of a+ca+c is:
3535
2424
−12-12
−61-61
−63-63
Answer: D
Concepts:polynomialVieta’s Formulas
Small hint:
The missing x3x^3 coefficient makes the sum of all four roots zero
Big hint:
Use the fourth root to compute the pairwise sum aa and product cc
Solution:
The fourth root is −6-6 because the root sum is zero. The sum of pairwise products is a=2+3−6+6−12−18=−25, \begin{aligned} a&=2+3-6+6\\ &\quad-12-18=-25, \end{aligned} while the product is c=(1)(2)(3)(−6)=−36.c=(1)(2)(3)(-6)=-36. Thus a+c=−61.a+c=-61.
Therefore, the correct answer is D.
LIVE by Po-Shen Loh
Programs

LIVE Classes

Self-Paced Classes

Stars

Scholarship

About Us

Who Is Po-Shen Loh?

Email Contact

Newsletter

Jobs

Become a Star

For a more Thought Full world.

© 2026 Expii, Inc.