Respuesta :
Answer:
f(x) = x^3 + 7x^2 + 7x -15
Step-by-step explanation:
f(x) = (x+5)(x+3)(x-1)
f(x) = (x^2 + 3x + 5x + 15)(x-1)
f(x) = (x^2 + 8x + 15)(x-1)
f(x) = x^3 + 8x^2 + 15x -x^2 -8x -15
simplify
f(x) = x^3 + 7x^2 + 7x -15
Answer:
[tex]f(x) = (x + 5)\, (x + 3)\, (x - 1)[/tex].
Step-by-step explanation:
By the factor theorem, if a constant [tex]a[/tex] is zero of the polynomial [tex]f(x)[/tex], [tex](x - a)[/tex] would be a factor of this polynomial. (Notice how [tex]x = a[/tex] would indeed set the value of [tex](x - a)\![/tex] to [tex]0[/tex].)
For instance, since [tex](-5)[/tex] is a zero of the polynomial [tex]f(x)[/tex], [tex](x - (-5))[/tex] would be a factor of [tex]f(x)\![/tex]. Simplify this expression to get [tex](x + 5)[/tex].
Likewise, the zero [tex](-3)[/tex] would correspond to the factor [tex](x + 3)[/tex], while the zero [tex]1[/tex] would correspond to the factor [tex](x - 1)[/tex].
All three of these factors above are linear, and the degree of the variable [tex]x[/tex] in each factor is [tex]1[/tex]. Multiplying three such linear factors would give a polynomial of degree [tex]3[/tex].
Given the three factors, the expression of [tex]f(x)[/tex] in factored form would be:
[tex]f(x) = m\, (x + 5)\, (x + 3)\, (x - 1)[/tex] for some constant [tex]m[/tex].
When this expression is expanded, the constant [tex]m[/tex] would be the coefficient of the [tex]x^{3}[/tex] term (the leading term.) In other words, [tex]m\![/tex] is the leading coefficient of [tex]f(x)[/tex]. This question has required this coefficient to be [tex]1[/tex]. Thus, [tex]m = 1[/tex]. The expression of [tex]f(x)\![/tex] in factored form would be:
[tex]f(x) = (x + 5)\, (x + 3)\, (x - 1)[/tex].
