High School

If the roots of the equation
3x² - 5x + q = 0 are equal, then what is the value of q?

(1) 2
(2) 5/12
(3) 12/25
(4) 25/12

Answer :

To find the value of [tex]q[/tex] such that the roots of the quadratic equation [tex]3x^2 - 5x + q = 0[/tex] are equal, we apply the condition for equal roots in a quadratic equation.

For a quadratic equation [tex]ax^2 + bx + c = 0[/tex], the roots are equal if the discriminant is zero. The discriminant [tex]\Delta[/tex] is given by:

[tex]\Delta = b^2 - 4ac[/tex]

In the equation [tex]3x^2 - 5x + q = 0[/tex], we have:

  • [tex]a = 3[/tex]
  • [tex]b = -5[/tex]
  • [tex]c = q[/tex]

The condition for equal roots is:

[tex](-5)^2 - 4 \cdot 3 \cdot q = 0[/tex]
[tex]25 - 12q = 0[/tex]

Solving for [tex]q[/tex], we rearrange the equation:

[tex]25 = 12q[/tex]
[tex]q = \frac{25}{12}[/tex]

Therefore, the value of [tex]q[/tex] that makes the roots of the equation equal is [tex]\frac{25}{12}[/tex].

The chosen multiple choice option is (4) [tex]\frac{25}{12}[/tex].