The area of Vincent’s rectangular poster is x2 – 17x – 60. Which of the following represents a dimension of the poster?

Group of answer choices

(x – 3)

(x + 12)

(x – 20)

(x – 5)

1 answer

To determine which expression represents a dimension of Vincent's rectangular poster, we first need to factor the area expression \( x^2 - 17x - 60 \).

To factor \( x^2 - 17x - 60 \), we need to find two numbers that multiply to \(-60\) (the constant term) and add to \(-17\) (the coefficient of the linear term).

The pairs of factors of \(-60\) are:

  • \(1, -60\)
  • \(-1, 60\)
  • \(2, -30\)
  • \(-2, 30\)
  • \(3, -20\)
  • \(-3, 20\)
  • \(4, -15\)
  • \(-4, 15\)
  • \(5, -12\)
  • \(-5, 12\)
  • \(6, -10\)
  • \(-6, 10\)

Among these pairs, the numbers \(-20\) and \(3\) multiply to \(-60\) and add to \(-17\).

Thus, we can factor the expression as follows:

\[ x^2 - 17x - 60 = (x - 20)(x + 3) \]

Now, we can see that the dimensions of the poster can be represented by the factors \( (x - 20) \) and \( (x + 3) \).

Reviewing the answer choices, we find:

  • \((x - 3)\)
  • \((x + 12)\)
  • \((x - 20)\)
  • \((x - 5)\)

Among these, \((x - 20)\) is the only factor we found when we factored the area.

Therefore, a dimension of the poster is represented by \((x - 20)\).