```latex
[tex]$
\begin{array}{l}
d(x)=\sqrt{x+5} \\
m(x)=5x-3 \\
a(x)=x+2 \\
c(x)=5x^2+17x-12 \\
\end{array}
$[/tex]

Find and simplify:
a. [tex]$(d \circ a)(x)$[/tex]

b. [tex]$(d \circ a)(2)$[/tex]

c. [tex]$(c \circ m)(x)$[/tex]

d. [tex]$(m \circ c)(x)$[/tex]
```



Answer :

Let's go through the problem step-by-step to find and simplify each of the given composite functions:

### a. [tex]\((d \circ a)(x)\)[/tex]

To find [tex]\((d \circ a)(x)\)[/tex], we need to evaluate the function [tex]\(d\)[/tex] at the value given by [tex]\(a(x)\)[/tex]:

1. Define [tex]\(a(x)\)[/tex]: [tex]\(a(x) = x + 2\)[/tex]
2. Substitute [tex]\(a(x)\)[/tex] into [tex]\(d(x)\)[/tex]:
[tex]\[ (d \circ a)(x) = d(a(x)) = d(x + 2) \][/tex]
3. Define [tex]\(d(x)\)[/tex]: [tex]\(d(x) = \sqrt{x + 5}\)[/tex]
4. Substitute [tex]\(x + 2\)[/tex] into [tex]\(d(x)\)[/tex]:
[tex]\[ d(x + 2) = \sqrt{(x + 2) + 5} = \sqrt{x + 7} \][/tex]

Thus, the simplified form of [tex]\((d \circ a)(x)\)[/tex] is:
[tex]\[ (d \circ a)(x) = \sqrt{x + 7} \][/tex]

### b. [tex]\((d \circ a)(2)\)[/tex]

To find [tex]\((d \circ a)(2)\)[/tex], we use the simplified form from part (a) and substitute [tex]\(x = 2\)[/tex]:

1. Use the result from (a):
[tex]\[ (d \circ a)(x) = \sqrt{x + 7} \][/tex]
2. Substitute [tex]\(x = 2\)[/tex]:
[tex]\[ (d \circ a)(2) = \sqrt{2 + 7} = \sqrt{9} = 3 \][/tex]

So, [tex]\((d \circ a)(2) = 3\)[/tex].

### c. [tex]\((c \circ m)(x)\)[/tex]

To find [tex]\((c \circ m)(x)\)[/tex], we need to evaluate the function [tex]\(c\)[/tex] at the value given by [tex]\(m(x)\)[/tex]:

1. Define [tex]\(m(x)\)[/tex]: [tex]\(m(x) = 5x - 3\)[/tex]
2. Substitute [tex]\(m(x)\)[/tex] into [tex]\(c(x)\)[/tex]:
[tex]\[ (c \circ m)(x) = c(m(x)) = c(5x - 3) \][/tex]
3. Define [tex]\(c(x)\)[/tex]: [tex]\(c(x) = 5x^2 + 17x - 12\)[/tex]
4. Substitute [tex]\(5x - 3\)[/tex] into [tex]\(c(x)\)[/tex]:
[tex]\[ c(5x - 3) = 5(5x - 3)^2 + 17(5x - 3) - 12 \][/tex]
5. Simplify the expression:
[tex]\[ (5x - 3)^2 = 25x^2 - 30x + 9 \][/tex]
[tex]\[ c(5x - 3) = 5(25x^2 - 30x + 9) + 17(5x - 3) - 12 \][/tex]
[tex]\[ = 125x^2 - 150x + 45 + 85x - 51 - 12 \][/tex]
[tex]\[ = 125x^2 - 65x - 18 \][/tex]

Thus, the simplified form of [tex]\((c \circ m)(x)\)[/tex] is:
[tex]\[ (c \circ m)(x) = 125x^2 - 65x - 18 \][/tex]

### d. [tex]\((m \circ c)(x)\)[/tex]

To find [tex]\((m \circ c)(x)\)[/tex], we need to evaluate the function [tex]\(m\)[/tex] at the value given by [tex]\(c(x)\)[/tex]:

1. Define [tex]\(c(x)\)[/tex]: [tex]\(c(x) = 5x^2 + 17x - 12\)[/tex]
2. Substitute [tex]\(c(x)\)[/tex] into [tex]\(m(x)\)[/tex]:
[tex]\[ (m \circ c)(x) = m(c(x)) = m(5x^2 + 17x - 12) \][/tex]
3. Define [tex]\(m(x)\)[/tex]: [tex]\(m(x) = 5x - 3\)[/tex]
4. Substitute [tex]\(5x^2 + 17x - 12\)[/tex] into [tex]\(m(x)\)[/tex]:
[tex]\[ m(5x^2 + 17x - 12) = 5(5x^2 + 17x - 12) - 3 \][/tex]
5. Simplify the expression:
[tex]\[ = 25x^2 + 85x - 60 - 3 \][/tex]
[tex]\[ = 25x^2 + 85x - 63 \][/tex]

Thus, the simplified form of [tex]\((m \circ c)(x)\)[/tex] is:
[tex]\[ (m \circ c)(x) = 25x^2 + 85x - 63 \][/tex]

### Summary

a. [tex]\((d \circ a)(x) = \sqrt{x + 7}\)[/tex]

b. [tex]\((d \circ a)(2) = 3\)[/tex]

c. [tex]\((c \circ m)(x) = 125x^2 - 65x - 18\)[/tex]

d. [tex]\((m \circ c)(x) = 25x^2 + 85x - 63\)[/tex]