By Vieta's formulas, if the roots of 2x3−x2+3x−5=02x^3 - x^2 + 3x - 5 = 02x3−x2+3x−5=0 are r1,r2,r3r_1, r_2, r_3r1,r2,r3, find r1+r2+r3r_1 + r_2 + r_3r1+r2+r3.
frac12\\frac{1}{2}frac12
−frac12-\\frac{1}{2}−frac12
frac52\\frac{5}{2}frac52
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