Respuesta :
Answer:
[tex]f(g(-7))=10[/tex]
Step-by-step explanation:
We have the two functions:
[tex]\displaystyle f(x)=\frac{1}{3}x+7\text{ and } g(x)=-2x-5[/tex]
And we want to find:
[tex]f(g(-7))[/tex]
So, we will first find g(-7). We know that:
[tex]g(x)=-2x-5[/tex]
Then by substitution:
[tex]g(-7)=-2(-7)-5[/tex]
Evaluate. Multiply:
[tex]g(-7)=14-5=9[/tex]
Therefore, we can rewrite our expression as:
[tex]f(g(-7))=f(9)[/tex]
Since we know that:
[tex]\displaystyle f(x)=\frac{1}{3}x+7[/tex]
By substitution:
[tex]\displaystyle f(9)=\frac{1}{3}(9)+7[/tex]
Evaluate:
[tex]f(9)=3+7=10[/tex]
Therefore:
[tex]f(g(-7))=10[/tex]
Answer:
[tex]\boxed {\boxed {\sf f(g(-7))= 10}}[/tex]
Step-by-step explanation:
We are asked to find f(g(-7)) given these 2 functions:
- [tex]f(x)=\frac{1}{3}x+7[/tex]
- [tex]g(x)= -2x-5[/tex]
We must work from the inside out, so first find g(-7).
1. g(-7)
The function for g is:
[tex]g(x)= -2x-5[/tex]
Since we want to find g(-7), plug -7 in for x.
[tex]g(-7)= -2(-7)-5[/tex]
Solve according the PEMDAS: Parentheses, Exponents, Multiplication, Division, Addition, Subtraction.
Multiply -2 and -7.
[tex]g(-7)=14-5[/tex]
Subtract 5 from 14.
[tex]g(-7)=9[/tex]
2. f(9)
Refer back to the original problem: f(g(-7))
Since we found that g(-7) is 9, we can substitute 9 in: f(9)
The function for f is:
[tex]f(x)= \frac{1}{3} x+7[/tex]
Plug 9 in for x.
[tex]f(9)=\frac{1}{3}(9)+7[/tex]
Solve according to PEMDAS and multiply 1/3 and 9.
[tex]f(9)=3+7[/tex]
Add 3 and 7.
[tex]f(9)=10[/tex]
f(g(-7) is equal to 10