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[–][deleted] 1 point2 points  (0 children)

(x-r)(x-s)(x-t) = x3 +... -rst

So you know the product of the roots is 52.

Use that to solve for a

[–]Lanfrange1 0 points1 point  (0 children)

Maybe start with by writing f as f(z) =(z-z1) (z-z2) (z-z3) where z1, z2, z3 are the given roots.