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-3 is a root of the quadratic equation 2x2 +px – 15 = 0. For what value of q , the equation p(x2 + x ) + q= 0 has equal roots?​
  • a)
    1/4
  • b)
    2
  • c)
    14
  • d)
    1/2
Correct answer is option 'A'. Can you explain this answer?
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-3 is a root of the quadratic equation 2x2+px – 15 = 0. For what...
**Given Information:**
- The quadratic equation is given as 2x^2 + px + 15 = 0.
- The root of the equation is -3.
- We need to find the value of q for which the equation p(x^2 + x) + q = 0 has equal roots.

**Solution:**
To find the value of q, we need to determine the conditions for the roots of the quadratic equation p(x^2 + x) + q = 0 to be equal.

**Condition for Equal Roots:**
For a quadratic equation ax^2 + bx + c = 0 to have equal roots, the discriminant (b^2 - 4ac) must be equal to zero.

**Finding the Discriminant:**
Let's find the discriminant for the given equation p(x^2 + x) + q = 0.

The given equation can be rewritten as px^2 + px + qx + q = 0.

Comparing it with the standard form ax^2 + bx + c = 0, we can determine the values of a, b, and c as follows:
- a = p
- b = p + q
- c = q

The discriminant is calculated as follows:
D = (b^2 - 4ac)
= [(p + q)^2 - 4pq]

**Condition for Equal Roots:**
To have equal roots, the discriminant D must be equal to zero.

Therefore, we have the equation: (p + q)^2 - 4pq = 0.

**Substituting the Value of p:**
We know that -3 is one of the roots of the quadratic equation 2x^2 + px + 15 = 0.

Substituting x = -3 into the equation, we get:
2(-3)^2 + p(-3) + 15 = 0
18 - 3p + 15 = 0
33 - 3p = 0
3p = 33
p = 11

**Substituting the Value of p in the Equation:**
Now, substitute the value of p = 11 into the equation (p + q)^2 - 4pq = 0.

(11 + q)^2 - 4(11)(q) = 0
121 + 22q + q^2 - 44q = 0
q^2 - 22q + 121 - 44q = 0
q^2 - 66q + 121 = 0

**Finding the Value of q:**
To find the value of q, we need to solve the quadratic equation q^2 - 66q + 121 = 0.

By factoring or using the quadratic formula, we can find that q = 1/4 and q = 121 are the solutions of the equation.

However, we need to select the value of q for which the equation has equal roots.

Since the question asks for the value of q where the equation has equal roots, the correct answer is q = 1/4 (option A).
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-3 is a root of the quadratic equation 2x2+px – 15 = 0. For what value of q , the equation p(x2+ x ) + q= 0 has equal roots?​a)1/4b)2c)14d)1/2Correct answer is option 'A'. Can you explain this answer? for Class 10 2025 is part of Class 10 preparation. The Question and answers have been prepared according to the Class 10 exam syllabus. Information about -3 is a root of the quadratic equation 2x2+px – 15 = 0. For what value of q , the equation p(x2+ x ) + q= 0 has equal roots?​a)1/4b)2c)14d)1/2Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 10 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for -3 is a root of the quadratic equation 2x2+px – 15 = 0. For what value of q , the equation p(x2+ x ) + q= 0 has equal roots?​a)1/4b)2c)14d)1/2Correct answer is option 'A'. Can you explain this answer?.
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