Answer:
1 - 3, 2 - 5, 3 - 4, 4 - 6, 5 - 1, 6 - 2.
Explanation:
We have,
h(x) = 5-3x and

So, according to the options, we have,
1. k(x) = (5g + 3h)(x)
Now,

i.e.

i.e.

i.e.

2. k(x) = (3h - 5g)(x)
Now,

i.e.

i.e.

i.e.

3. k(x) = (3g + 5h)(x)
Now,

i.e.

i.e.

i.e.

4. k(x) = (5h - 3g)(x)
Now,

i.e.

i.e.

i.e.

5. k(x) = (h - g)(x)
Now,

i.e.

i.e.

i.e.

6. k(x) = (g + h)(x)
Now,

i.e.

i.e.

Thus, we have the matches as,
1. k(x) = (5g + 3h)(x) ---------------- 5. k(x)=40-5(3^x)-9x
2. k(x) = (3h - 5g)(x) ---------------- 6. k(x)=5(3^x)-9x-10
3. k(x) = (3g + 5h)(x) ---------------- 1. k(x)=40-3^x+1-15x
4. k(x) = (5h - 3g)(x) ----------------- 3. k(x)=10+3^x+1-15x
5. k(x) = (h - g)(x) ----------------- 2. k(x)=3^x-3x
6. k(x) = (g + h)(x) ----------------- 4. k(x)=10-3^x-3x