Algebra (Railway Maths) (Part – V)

Total Questions: 50

31. If one root of the equation (k + 1)x² - 13kx + 7 - 2k = 0 is the reciprocal of the other, then the value of k is: [Group D 29/09/2022 (Evening) ]

Correct Answer: (b) 2
Solution:

32. Find the answer of given question? [Group D 29/09/2022 (Evening) ]

Correct Answer: (c) 2√5
Solution:

33. If a = (3/7)² ÷ (9/7)⁰, then find the value of a⁻². [Group D 30/09/2022 (Afternoon)]

Correct Answer: (a) 2401/81
Solution:

34. Solve the given equation (5x² − 5) + 5(−x² + 2x − 7) = 0 [Group D 30/09/2022 (Afternoon)]

Correct Answer: (a) x = 4
Solution:

(5x² - 5) + 5(-x² + 2x - 7) = 0
5x 2 - 5 - 5x 2 + 10x - 35 = 0
⇒ 10x = 40 ⇒ x = 4

35. Find the answer of given question? [Group D 30/09/2022 (Afternoon)]

Correct Answer: (b) 15
Solution:

36. The value of the discriminant of the quadratic equation 9x + 2x² = 5 is: [Group D 30/09/2022 (Evening)]

Correct Answer: (d) 121
Solution:

Equation = 2x 2 + 9x - 5 = 0
Discriminant = b 2 – 4ac
= (9) 2 – 4 × 2 × (- 5) = 81 + 40 = 121

37. The sum of a number and its reciprocal is - 2. Find the quadratic equation associated with the situation and also the number. [Group D 06/10/2022 (Morning) ]

Correct Answer: (c) x² + 2x + 1 = 0, x = -1
Solution:

38. Find the answer of given question? [Group D 06/10/2022 (Afternoon) ]

Correct Answer: (d) x² - 1/x²
Solution:

39. If 4a + 3b = 2c, then find (4a)³ + (3b)³ + (−2c)³. [Group D 06/10/2022 (Afternoon)]

Correct Answer: (a) −72abc
Solution:

40. Find the quadratic equation whose roots are √3 + 1 and √3 − 1. [Group D 06/10/2022 (Afternoon)]

Correct Answer: (c) x² − 2√3x + 2 = 0
Solution: