If [tex]f(x) = 3^x + 10x[/tex] and [tex]g(x) = 5x - 3[/tex], find [tex](f - g)(x)[/tex].

A. [tex]3^x - 5x + 3[/tex]

B. [tex]3^x + 5x + 3[/tex]

C. [tex]18x - 3[/tex]

D. [tex]3^x + 15x - 3[/tex]



Answer :

To solve the problem of finding [tex]\((f - g)(x)\)[/tex] given the functions [tex]\(f(x) = 3^x + 10x\)[/tex] and [tex]\(g(x) = 5x - 3\)[/tex], follow these steps:

1. Write down the given functions:
[tex]\(f(x) = 3^x + 10x\)[/tex]
[tex]\(g(x) = 5x - 3\)[/tex]

2. Set up the expression for [tex]\((f - g)(x)\)[/tex]:
[tex]\((f - g)(x) = f(x) - g(x)\)[/tex]

3. Substitute the given functions into the expression:
[tex]\[ (f - g)(x) = (3^x + 10x) - (5x - 3) \][/tex]

4. Distribute the subtraction to each term in [tex]\(g(x)\)[/tex]:
[tex]\[ (f - g)(x) = 3^x + 10x - 5x + 3 \][/tex]
Here, we need to be careful with the negative sign when subtracting [tex]\(g(x)\)[/tex].

5. Combine like terms:
- Combine [tex]\(10x\)[/tex] and [tex]\(-5x\)[/tex]:
[tex]\[ 10x - 5x = 5x \][/tex]

- The constant term will simply be [tex]\(+3\)[/tex].

So, the simplified expression is:
[tex]\[ (f - g)(x) = 3^x + 5x + 3 \][/tex]

This matches option B. Therefore, the answer is:

[tex]\[ \boxed{3^x + 5x + 3} \][/tex]