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30 Quadratic problems Questions and Answers
30 solved Quadratic problems questions with step-by-step explanations. Includes formulas, shortcuts, and tips for placement tests and competitive exams.
Advanced quadratic problems questions for experienced learners. These medium-to-hard questions test deeper understanding and are ideal for those who have already mastered the basics. Each question includes a detailed explanation.
Key Formulas
ax² + bx + c = 0
Roots: x = [-b ± sqrt(b²-4ac)] / 2a
Sum of roots = -b/a, Product of roots = c/a
Discriminant: D = b² - 4ac (D>0 real, D=0 equal, D<0 complex)
Q1
Medium
For x^2 - 10x + 25 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 10.
Q2
Medium
For x^2 - 18x + 77 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 18.
Q3
Medium
For x^2 - 10x + 21 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 21/1 = 21.
Q4
Medium
For x^2 - 11x + 18 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 11.
Q5
Medium
For x^2 - 20x + 100 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 100/1 = 100.
Q6
Medium
For x^2 - 6x + 5 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 5/1 = 5.
Q7
Medium
For x^2 - 19x + 90 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 90/1 = 90.
Q8
Medium
For x^2 - 10x + 16 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 16/1 = 16.
Q9
Medium
For x^2 - 14x + 48 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 48/1 = 48.
Q10
Medium
For x^2 - 9x + 18 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 9.
Q11
Medium
For x^2 - 8x + 7 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 7/1 = 7.
Q12
Medium
For x^2 - 5x + 4 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 4/1 = 4.
Q13
Medium
Find roots of x^2 + 11x + 30 = 0
Explanation:
x^2 + 11x + 30 = (x+6)(x+5). Roots are -6 and -5.
Q14
Medium
For x^2 - 9x + 20 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 9.
Q15
Medium
For x^2 - 15x + 54 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 15.
Q16
Medium
For x^2 - 16x + 48 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 16.
Q17
Medium
For x^2 - 18x + 72 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 18.
Q18
Medium
Find roots of x^2 + 8x + 16 = 0
Explanation:
x^2 + 8x + 16 = (x+4)(x+4). Roots are -4 and -4.
Q19
Medium
For x^2 - 9x + 8 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 8/1 = 8.
Q20
Medium
For x^2 - 17x + 70 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 70/1 = 70.
Q21
Medium
For x^2 - 12x + 35 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 35/1 = 35.
Q22
Medium
For x^2 - 12x + 27 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 12.
Q23
Medium
For x^2 - 4x + 4 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 4.
Q24
Medium
For x^2 - 7x + 10 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 7.
Q25
Medium
For x^2 - 16x + 60 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 16.
Q26
Medium
For x^2 - 13x + 36 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 13.
Q27
Medium
For x^2 - 16x + 60 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 60/1 = 60.
Q28
Medium
For x^2 - 12x + 20 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 12.
Q29
Medium
For x^2 - 17x + 72 = 0, what is the product of roots?
Explanation:
Product of roots = c/a = 72/1 = 72.
Q30
Medium
For x^2 - 20x + 100 = 0, what is the sum of roots?
Explanation:
For ax^2+bx+c=0, sum = -b/a. Here sum = 20.
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