Question

The sum of roots of quadratic equation 3x2 – 9x + 5 = 0 is Select one:

a. 3

b. 6

c. -3

d. 2

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Answer 1

Given,

The equation as $3x^{2} - 9x + 5 = 0$

To find,

Sum of the roots in the quadratic equation

Solution,

Let's find the roots for the given equation first.

$3x^{2} - 9x + 5 = 0$

Quadratic roots formula is,

$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a} .$

$x=\frac{-9\pm\sqrt{-9^2-4(3)(5)}}{2(3)} .$

$x=\frac{9\pm\sqrt21}{6} .$

Now, lets add the roots, we get $\frac{18}{6}$ = 3

Hence, sum of the roots for given equation is 3.

Answer 2

a. 3

Step-by-step explanation:

Let the roots of the equation be α and β.

We know that, α+β = -b/a (i)

In the equation 3x²-9x+5 = 0,

a = 3, b = -9, c = 5

Putting the values in (i), we get

α+β = -(-9)/3

α+β = 9/3

α+β = 3

Therefore, the sum of the roots of the quadratic equation is 3.