Answer:
[tex]Degree = 3[/tex]
Step-by-step explanation:
Given
[tex]k(x) = x + 1[/tex]
[tex]m(x) = x - 4[/tex]
[tex]n(x) = x + 5[/tex]
[tex]f(x) = k(x) * m(x) * n(x)[/tex]
Required
The degree of f(x)
First, calculate f(x)
[tex]f(x) = k(x) * m(x) * n(x)[/tex]
[tex]f(x) = (x +1) * (x - 4) * (x + 5)[/tex]
Expand
[tex]f(x) = (x +1) * (x^2 - 4x + 5x - 20)[/tex]
[tex]f(x) = (x +1) * (x^2 + x - 20)[/tex]
Further Expand
[tex]f(x) = x^3 + x^2 - 20x +x^2 + x - 20[/tex]
Collect like terms
[tex]f(x) = x^3 + x^2 +x^2 - 20x + x - 20[/tex]
[tex]f(x) = x^3 + 2x^2 - 19x- 20[/tex]
The degree of f(x) is the highest power of x.
Hence:
[tex]Degree = 3[/tex]
