Answer:
If that's the whole question then what exactly are we trying to solve here?
Step-by-step explanation:
1. Calculate the volume of entire cube as if it was a solid rectangle:
Length x width x height=
20x16x12 = 3,940 cubic inches
2. Calculate the volume of the "missing"
Piece and subtract:
Length x width x height=
20x8x6 = 960 cubic inches
(notice you can find the height of the missing piece by subtracting 12-6)
So your answer is 3,940-960 = 2,980 cubic inches inside the steps
9) C.
10)A.
11) $75
Those are all the answers that you needed.
"31-inch piece of steel is cut into three pieces"
Call the pieces a,b,c
a + b + c = 31
"second piece is twice as long as the first piece"
b = 2a
"third piece is one inch more than seven times the length of the first piece"
c = 1 + 7a
Ok, we have our equations, let's substitute the second and third into the first.
a + 2a + 1 + 7a = 31
10a + 1 = 31
10a = 30
a = 30/10 = 3
b = 2a = 6
c = 1 + 7a = 22
Check: 3 + 6 + 22 = 31, good
Answer: 3 inches, 6 inches, 22 inches