Multiple choice

Find the value of $z$, if the sum of roots of equation is $10$. $\displaystyle 8{ x }^{ 2 }-zx+18=0$

  1. $40$
  2. $80$
  3. $10$
  4. $-80$
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B Correct answer
Explanation

For a quadratic equation ax^2 + bx + c = 0, the sum of roots is -b/a. Here, -(-z)/8 = 10, so z/8 = 10, z = 80.

AI explanation

Using the relationship between roots and coefficients for a quadratic equation ax^2 + bx + c = 0, the sum of the roots is given by -b/a. Here, a = 8, b = -z and c = 18, so the sum of the roots is -(-z)/8, which simplifies to z/8. We are given that the sum of the roots is 10, so z/8 = 10. Multiplying both sides by 8 gives z = 80.

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