Answer:
1) 3|x|=[0; infinity). there is no infinity sign lol
2) 3|x|= (0; infinity)
It would be 1n - 12 + 8y.
4n - 3n = 1n
12 + 8y don’t mix so we can leave it.
Therefore: 1n - 12 + 8y
For this case we have:
Cost of manufactures of T-shirts 
where x represents the number of T-shirts
Part A:
Substituting
in the total cost equation you have to:

Thus, the cost of 8 shirts will be 
Part B:
If
then

Thus, the cost of 12 shirts will be 
Answer:

Answer:
See explanation
Step-by-step explanation:
Solution:-
- We will use the basic formulas for calculating the volumes of two solid bodies.
- The volume of a cylinder ( V_l ) is represented by:

- Similarly, the volume of cone ( V_c ) is represented by:

Where,
r : The radius of cylinder / radius of circular base of the cone
h : The height of the cylinder / cone
- We will investigate the correlation between the volume of each of the two bodies wit the radius ( r ). We will assume that the height of cylinder/cone as a constant.
- We will represent a proportionality of Volume ( V ) with respect to ( r ):

Where,
C: The constant of proportionality
- Hence the proportional relation is expressed as:
V∝ r^2
- The volume ( V ) is proportional to the square of the radius. Now we will see the effect of multiplying the radius ( r ) with a positive number ( a ) on the volume of either of the two bodies:

- Hence, we see a general rule frm above relation that multiplying the result by square of the multiple ( a^2 ) will give us the equivalent result as multiplying a multiple ( a ) with radius ( r ).
- Hence, the relations for each of the two bodies becomes:

&

The perimeter = 4 * length of a semicircle of radius 5 == 4* pi * 5 = 20 pi cm
The area of one of the clear parts = 1/2 area of square - area semicircle
= 1/2 * 10^2 - 1/2 pi *5^2 = 50 - 12.5pi
So area of shaded parts = area of square - 4 (50 - 12.5pi)
= 100 - 200 + 100pi = (100pi - 100) cm^2