This is aptitude questions and answers section on Quadratic Equations with explanation for various interview, competitive examinations and entrance tests. In this section, we have provided quadratic equations questions and answers with solutions. So, students or job aspirants can practice these questions for their exam preparation.
__Quadratic Equations Questions - Quiz Details__

__Quadratic Equations Formula__

1. The general quadratic equation is ax^{2}+bx+c=0.

Online Test Name |
Quadratic Equations |

Exam Type |
Multiple Choice Questions |

Category |
Aptitude Quiz |

Number of Questions |
30 |

1. Find the roots of the quadratic equation: x^{2} + 2x - 15 = 0?
### Answer & Explanation

### Workspace

### Report Error

Answer: Option A

Explanation:

x^{2} + 5x - 3x - 15 = 0

x(x + 5) - 3(x + 5) = 0

(x - 3)(x + 5) = 0

=> x = 3 or x = -5.

2. Find the roots of the quadratic equation: 2x^{2} + 3x - 9 = 0?
### Answer & Explanation

### Workspace

### Report Error

Answer: Option B

Explanation:

2x^{2} + 6x - 3x - 9 = 0

2x(x + 3) - 3(x + 3) = 0

(x + 3)(2x - 3) = 0

=> x = -3 or x = 3/2.

3. The roots of the equation 3x^{2} - 12x + 10 = 0 are?
### Answer & Explanation

### Workspace

### Report Error

Answer: Option D

Explanation:

The discriminant of the quadratic equation is (-12)^{2} - 4(3)(10) i.e., 24. As this is positive but not a perfect square, the roots are irrational and unequal.

4. If the roots of a quadratic equation are 20 and -7, then find the equation?
### Answer & Explanation

### Workspace

### Report Error

Answer: Option C

Explanation:

Any quadratic equation is of the form

x^{2} - (sum of the roots)x + (product of the roots) = 0 ---- (1)

where x is a real variable. As sum of the roots is 13 and product of the roots is -140, the quadratic equation with roots as 20 and -7 is: x^{2} - 13x - 140 = 0.

5. The sum and the product of the roots of the quadratic equation x^{2} + 20x + 3 = 0 are?
### Answer & Explanation

### Workspace

### Report Error

Answer: Option E

Explanation:

Sum of the roots and the product of the roots are -20 and 3 respectively.