Respuesta :

Answer:

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

2) [tex](f-g)(x)=2x^2+x[/tex]

3) [tex](f \cdot g)(x)=2x^3-4x^2-9x+9[/tex]

Step-by-step explanation:

So we have the two functions:

[tex]f(x)=2x^2+2x-3\text{ and } g(x)=x-3[/tex]

And we want to find (f+g)(x), (f-g)(x), and (f*g)(x).

1)

(f+g)(x) is the same to f(x)+g(x). Substitute:

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

Combine like terms:

[tex]=(2x^2)+(2x+x)+(-3-3)[/tex]

Add:

[tex]=2x^2+3x-6[/tex]

So:

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

2)

(f-g)(x) is the same to f(x)-g(x). So:

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

Distribute:

[tex]=(2x^2+2x-3)+(-x+3)[/tex]

Combine like terms:

[tex]=(2x^2)+(2x-x)+(-3+3)[/tex]

Simplify:

[tex]=2x^2+x[/tex]

So:

[tex](f-g)(x)=2x^2+x[/tex]

3)

(f*g)(x) is the same to f(x)*g(x). Thus:

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

Distribute:

[tex]=(2x^2+2x-3)(x)+(2x^2+2x-3)(-3)[/tex]

Distribute:

[tex]=(2x^3+2x^2-3x)+(-6x^2-6x+9)[/tex]

Combine like terms:

[tex]=(2x^3)+(2x^2-6x^2)+(-3x-6x)+(9)[/tex]

Simplify:

[tex]=2x^3-4x^2-9x+9[/tex]

So:

[tex](f \cdot g)(x)=2x^3-4x^2-9x+9[/tex]

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