The number -5 is anything but natural number.
It is an integer (Z) ,a rational number (Q) and a real number (R) .
Answer:
2376 square feet
Step-by-step explanation:
40 x 15 = 600
40 x 24 = 960
1/2 x (24 x 9) = 108
600 + 600 + 960 + 108 + 108 = 2376
For this case, the first thing we must do is define variables.
We have then:
x: number of pens
y: number of pencils
We now write the system of inequations:

The solution to the system of inequations is given by the shaded region.
Note: see attached image.