No 20.0000004 cannot be rational.
Answer:
Volume of one cube shaped block is, 0.125 cubic feet
Step-by-step explanation:
Volume of a cube(V) is given by:
.....[1]
where a is the edge length of the cube.
As per the statement:
Cube-shaped blocks are packed into a cube-shaped storage container. The edge of the storage container is 2 1/2 feet.
⇒
It is also given that:
The edge length of each block is 1/5 the edge length of the storage container
⇒
Substitute this in [1] we have;

Therefore, volume, in cubic feet, of one cube-shaped block is, 0.125
Answer:
x = 0
y = 5
z = -5.
Step-by-step explanation:
X-5y-z=-20
-2x-y-6z=25
-x-4y-z=-15
Add equation 1 and 3:
-9y - 2z = -35 .......... A
Multiply the first equation by 2:
2x - 10y - 2z = -40
Now add this to equation 2:
-11y -8z = -15.............B
Now multiply equation A by -4:
36y + 8x = 140.........C
Add equations B and C:
25y = 125
y = 5.
Substitute for y in equation A:
-9*5 - 2z = -35
2z = -45 + 35 = - 10
z = -5.
Now find x by substituting for y and z in the first equation:
x - 5(5) - (-5) = -20
x - 20 = -20
x = 0.