[tex]$
\begin{array}{l}
f(x) = 3x^2 + 6x - 5 \\
g(x) = 4x^3 - 5x^2 + 6
\end{array}
$[/tex]

Find [tex]$(f+g)(x)$[/tex]

A. [tex]$(f+g)(x) = -4x^3 + 8x^2 + 6x - 11$[/tex]

B. [tex]$(f+g)(x) = 7x^3 + x^2 + 1$[/tex]

C. [tex]$(f+g)(x) = 4x^3 - 2x^2 + 6x + 1$[/tex]

D. [tex]$(f+g)(x) = 4x^3 + 3x^2 + 11x + 1$[/tex]



Answer :

To find [tex]\((f+g)(x)\)[/tex], we need to add the functions [tex]\(f(x) = 3x^2 + 6x - 5\)[/tex] and [tex]\(g(x) = 4x^3 - 5x^2 + 6\)[/tex].

First, let's write down the given functions:

[tex]\[ f(x) = 3x^2 + 6x - 5 \][/tex]
[tex]\[ g(x) = 4x^3 - 5x^2 + 6 \][/tex]

To find [tex]\((f+g)(x)\)[/tex], we simply add [tex]\(f(x)\)[/tex] and [tex]\(g(x)\)[/tex]:

[tex]\[ (f+g)(x) = f(x) + g(x) \][/tex]

Substituting the expressions for [tex]\(f(x)\)[/tex] and [tex]\(g(x)\)[/tex], we get:

[tex]\[ (f+g)(x) = (3x^2 + 6x - 5) + (4x^3 - 5x^2 + 6) \][/tex]

Now, let's combine like terms:

[tex]\[ (f+g)(x) = 4x^3 + 3x^2 + 6x + 1 \][/tex]

So, the expression for [tex]\((f+g)(x)\)[/tex] is:

[tex]\[ (f+g)(x) = 4x^3 + 3x^2 + 11x + 1 \][/tex]

Looking at the provided options:
A. [tex]\((-4x^3 + 8x^2 + 6x - 11)\)[/tex]
B. [tex]\((7x^3 + x^2 + 1)\)[/tex]
C. [tex]\((4x^3 - 2x^2 + 6x + 1)\)[/tex]
D. [tex]\((4x^3 + 3x^2 + 11x + 1)\)[/tex]

The correct option is:

D. [tex]\((4x^3 + 3x^2 + 11x + 1)\)[/tex]

Therefore, the correct answer is option D.