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Find the sum of the solutions of this equation

Find the sum of the solutions of this equation-example-1
User Nneoma
by
8.2k points

2 Answers

1 vote

Answer:

39/20

Explanation:

find the solutions:


20x^2-39x-80=0


ax^2+bx+c=0

quadratic equation --> -b±
\sqrt{(b^2-4ac)/(2a) }

plug in variables --> (39±
\sqrt{(-39)^2-(4)(20)(-80))/(2*20)

solution 1 = -5/4

solution 2 = 16/5

-5/4+16/5 = -25/20+64/20 = 39/20

User Leemes
by
7.3k points
4 votes

Answer:

  • D) 39/20

================

According to Vieta's formula for quadratic equations:

  • If f(x) = ax2 + bx + c is a quadratic equation with roots α and β then, sum of roots = α + β = -b/a.

In the given equation, we have coefficients:

  • a = 20,
  • b = - 39.

Sum of the solutions would be:

  • - (-39)/20 =
  • 39/20

This is matching the last option.

User Statespace
by
8.0k points

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