Which of the following is one of the factors of x2 - 8x +15?
x² - 8x + 15 =
x² - 5x - 3 x + 15 =
x ∙ x - 5 ∙ x - 3 ∙ x + 15 =
x ∙ x - 5 ∙ x - 3 ∙ x - 3 ∙ ( - 5 ) =
x ( x - 5 ) - 3 ( x - 5 ) =
( x - 5 ) ( x - 3 )
To find the factors of a quadratic expression, you need to factorize it. The given quadratic expression is x^2 - 8x + 15.
To factorize the quadratic expression, you need to find two numbers that multiply to give the constant term (15) and add up to give the coefficient of the linear term (-8). In this case, the numbers are -5 and -3 because (-5) * (-3) = 15 and (-5) + (-3) = -8.
Now, you can rewrite the quadratic expression as (x - 5)(x - 3). These are the factors of the given quadratic expression.
Therefore, one of the factors of x^2 - 8x + 15 is (x - 5).