It has to be the third option 8(1+6) because 8+48= 56 and 8(1+6)= 56
The <em>instantaneous</em> rate of change of <em>g</em> with respect to <em>x</em> at <em>x = π/3</em> is <em>1/2</em>.
<h3>How to determine the instantaneous rate of change of a given function</h3>
The <em>instantaneous</em> rate of change at a given value of
can be found by concept of derivative, which is described below:

Where
is the <em>difference</em> rate.
In this question we must find an expression for the <em>instantaneous</em> rate of change of
if
and evaluate the resulting expression for
. Then, we have the following procedure below:




Now we evaluate
for
:

The <em>instantaneous</em> rate of change of <em>g</em> with respect to <em>x</em> at <em>x = π/3</em> is <em>1/2</em>. 
To learn more on rates of change, we kindly invite to check this verified question: brainly.com/question/11606037
I underlined the numbers you needed
Answer:
10 (X+1)
Step-by-step explanation:
Length = 2x + 5
Width = 3x
Perimeter of rectangle= 2(L + W)
P= 
P= 
Now, taking 5 as common
P= 
∴ Perimeter of rectangle= 