In the expression 4x¬¨‚â§ + bx – 45, where b …

Mathematics Questions

In the expression 4x¬¨‚â§ + bx – 45, where b is a constant, it can be factored as (hx + k)(x + j), with h, k, and j as integer constants. Which of the following must be an integer? a. b/h b. b/k c. 45/h d. 45/k

Short Answer

The process for factoring the quadratic expression 4x¬¨‚â§ + bx – 45 involves recognizing it as the product of two binomials, identifying integer pairs (k, j) whose product equals -45, and ensuring that 45/k yields an integer. By checking the factor pairs of -45, any suitable k will allow for this condition to be met, leading to the conclusion that Option D is the correct answer.

Step-by-Step Solution

Step 1: Understand the Quadratic Factorization

To solve the given quadratic expression, recognize that it can be rewritten in the form of two binomials, which generally looks like (hx + k)(x + j). In this specific case, we have to work with the expression 4x¬¨‚â§ + bx – 45. Our goal is to factor it properly, which will help us find the values of k and j.

Step 2: Identify the Conditions for Integer Values

Since the constant term is -45, it is crucial to remember that k and j must both be integers. The product of these constants (k ‚àöo j) should equal -45. Hence, we need to check the factors of -45 to see which combinations of k and j yield integer values. List the possible pairs of factors:

  • (1, -45)
  • (-1, 45)
  • (3, -15)
  • (-3, 15)
  • (5, -9)
  • (-5, 9)

Step 3: Find the Required Integer Value

For our expression to hold true, we must ensure that the fraction 45/k also results in an integer. Thus, we must determine which k from our pairs can divide 45 without leaving a remainder. As k takes integer values from our factor pairs, any valid selection will lead to 45/k being an integer. Finally, based on this understanding, the correct answer to the problem is Option D.

Related Concepts

Quadratic Factorization

Defining the process of rewriting a quadratic expression as the product of two binomials

Integer Values

Whole numbers that can be positive, negative, or zero, essential for ensuring factors are suitable for integer-based arithmetic

Factors

Values that can be multiplied together to yield another value, wherein the product of two integers must equal a specified constant (in this case, -45).

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