Question

Which of the following equations has the sum of its roots as 3?

(a) x² + 3x − 5 = 0

(b) −x² + 3x + 3 = 0

(c)

(d) 3x² − 3x − 3 = 0

Answer 1

Given the following quadratic equations

(a) x² + 3x − 5 = 0 (b) −x² + 3x + 3 = 0

(c) (d) 3x² − 3x − 3 = 0

We are to find out which of the above equations has sum of roots = 3.

The sum of the roots of the quadratic equation ax² + bx + c = 0 is given by .

For given equation (a)

a = 1, b = 3, c = −5

For given equation (b)

a = −1, b = 3, c = 3

For given equation (c)

For given equation (d)

a = 3, b = −3, c = −3

Hence option (b) is correct.