Concept:If α and β are the roots of a quadratic equation, then the equation is x2−(α+β)x+αβ=0.Explanation:The given roots are α=34 and β=−73.Sum of roots: α+β=34+(−73)=2128−9=2119.Product of roots: αβ=34×(−73)=−2112=−74.Substitute into the standard form: x2−2119x−74=0.Multiply through by 21 to clear fractions: 21x2−19x−12=0.Answer:21x2−19x−12=0, which is option A.