Polynomial Functions & Graphs Unit Test

Decompose the polynomial into linear factors (x ^ 2 - 7x + 6)(x ^ 2 + 3x - 18) (1 point)

1 answer

To decompose the polynomial \( (x^2 - 7x + 6)(x^2 + 3x - 18) \) into linear factors, we will first factor each quadratic polynomial separately.

  1. Factor the first polynomial: \( x^2 - 7x + 6 \)

    We need to find two numbers that multiply to \( 6 \) (the constant term) and add up to \( -7 \) (the coefficient of \( x \)). The numbers \( -1 \) and \( -6 \) satisfy these conditions.

    Thus, we can factor it as: \[ x^2 - 7x + 6 = (x - 1)(x - 6) \]

  2. Factor the second polynomial: \( x^2 + 3x - 18 \)

    Now, we need to find two numbers that multiply to \( -18 \) and add up to \( 3 \). The numbers \( 6 \) and \( -3 \) satisfy these conditions.

    Thus, we can factor it as: \[ x^2 + 3x - 18 = (x + 6)(x - 3) \]

  3. Combine the factors:

    Now, we can write the entire polynomial as a product of its linear factors: \[ (x^2 - 7x + 6)(x^2 + 3x - 18) = (x - 1)(x - 6)(x + 6)(x - 3) \]

So, the complete decomposition into linear factors is: \[ (x - 1)(x - 6)(x + 6)(x - 3) \]