Answer:
98
Step-by-step explanation:
So we have the two functions:

And we want to find the value of r(g(4)).
To do so, first find the value of g(4):

Multiply:

Subtract:

Now, substitute this into r(g(4)):

And substitute this value into r(x):

Square:

Subtract:

Therefore:

Give me a second to take a look at it
Answer and explanation:

(x + 6)(x + 7)
List the multiples of 42
42: 1 2 3 6 7 14 21 42
Then see which of the multiples add up to 13
1 x 42 = 42 --> 1 + 42
13
2 x 21 = 42 --> 2 + 21
13
3 x 14 = 42 --> 3 + 14
13
6 x 7 = 42 --> 6 + 7 = 13