Algebra Questions

Multiple choice
  1. lies between 2 and 3

  2. lies between – 1 and 0

  3. does not exist

  4. lies between 1 and 2

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let f(x) = 2x^3 + 3x + k. The derivative f'(x) = 6x^2 + 3 is always positive, meaning the function is strictly increasing. A strictly increasing function can have at most one real root, so it cannot have two distinct real roots in [0, 1].

Multiple choice
  1. x = 5, y = 2, z = 3

  2. x = 5, y = 3, z = - 2

  3. x = 5, y = - 3, z = 2

  4. x = 3, y = 2, z = 5

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Solving the system: 1) 2x + 5y - z = 27, 2) x + y + z = 6, 3) 2y + 5z = -4. From (2), z = 6 - x - y. Substitute into (1) and (3) to solve for x and y. Testing option B: 2(5) + 5(3) - (-2) = 10 + 15 + 2 = 27 (Correct). 5 + 3 + (-2) = 6 (Correct). 2(3) + 5(-2) = 6 - 10 = -4 (Correct).

Multiple choice
  1. x2 + 6x + 13 = 0

  2. x2 - 6x - 13 = 0

  3. x2 - 6x + 13 = 0

  4. 2x2 - 6x + 13 = 0

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If roots are 3 + 2i and 3 - 2i, the sum of roots = 6 and product = 3^2 + 2^2 = 13. The equation is x^2 - (sum)x + (product) = 0, which is x^2 - 6x + 13 = 0.

Multiple choice
  1. 5x2 + 2x + 4 = 0

  2. x2 - 8x + 16 = 0

  3. x2 - 11x + 2 = 0

  4. None of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A quadratic equation has imaginary roots if the discriminant D = b^2 - 4ac < 0. For 5x^2 + 2x + 4 = 0, D = 4 - 4(5)(4) = 4 - 80 = -76.