If r and s are roots of x^2 - 5x + 3 = 0, find r/s + s/r.

19/3 r/s + s/r = (r^2 + s^2)/(rs) = ((r+s)^2 - 2rs)/(rs) = (25 - 6)/3 = 19/3.

Nonlinear Equations in One Variable and Systems of Equations

SAT Math· difficulty 5/5

r

Explanation

r/s + s/r = (r^2 + s^2)/(rs) = ((r+s)^2 - 2rs)/(rs) = (25 - 6)/3 = 19/3

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