What is the LCD in its factored form of the following rational expression subtraction?%0D%0A%0D%0Ax2+2xx2+7x−8−xx−1%0D%0A%0D%0A(1 point)%0D%0AResponses

1 answer

To find the Least Common Denominator (LCD) of the rational expressions given, we first need to factor the denominators of the expressions. The expressions given are:

  1. \(\frac{x^2 + 2x}{x^2 + 7x - 8}\)
  2. \(\frac{x}{x - 1}\)

Step 1: Factor the denominators.

  1. For \(x^2 + 7x - 8\): We need to factor this quadratic expression. We will look for two numbers that multiply to \(-8\) and add to \(7\). The numbers are \(8\) and \(-1\).

    Therefore: \[ x^2 + 7x - 8 = (x + 8)(x - 1) \]

  2. The second denominator is already factored: \(x - 1\)

Step 2: Identify the unique factors.

  • From \((x + 8)(x - 1)\), we have the factors \(x + 8\) and \(x - 1\).
  • From the second denominator \(x - 1\), we only have \(x - 1\).

Step 3: Write the LCD as the product of the unique factors. The unique factors from both denominators are \(x + 8\) and \(x - 1\).

Thus, the Least Common Denominator (LCD) in its factored form is: \[ \boxed{(x + 8)(x - 1)} \]