Answer:
37 - 56 lb / ft3
0.6 - 0.9 103 kg / m3
Step-by-step explanation:
The density or hardness of wood varies by species, and the value is necessary to approximate the weight of lumber by volume. In this table, the density of different species of wood is expressed as weight in pounds per cubic foot and kilograms per cubic meter. The density will vary based on the moisture content of the wood.
The answer to the question is a
Answer: A; 6.3%
Step-by-step explanation:
Problem 1
For the first problem, we first want to find y so that we can plug it into the expression.
We can use elimination method for the system of equations to solve.
3x+3y=21
3x-y=5
We subtract both equations to eliminate x.
4y=16 [divide both sides by 4]
y=4
Now that we know y, we can plug it into the expression.
[divide]
[subtract]
We know that the answer is A.
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Problem 2
For the second problem, we need to know how to calculate percent error. The formula for precent error is 
. We know that the exact value is 80 because the buyer was supposed to given 80. 75 is the measured value because that was what the buyer was given.
[subtract]
[solve absolue value]
[divide]
[multiply]
Since the problem said to round to one decimal place, we know that the answer is 6.3%.
we have that
*-------------------------*--------------------------------*
E F G
EF=2x-12
FG= 3x-15
EG=23
we know that
EF + FG = EG
so
[2x - 12] + [3x - 15] = 23 simplify
5x - 27 = 23 add 27 to both sides
5x = 50 divide both sides by 5
x = 10
EF=2x-12-------> EF=2*10-12-------> EF=8
FG= 3x-15------> FG=3*10-15------> FG=15
therefore
the answer part a) is
the value of x is 10
the answer part b) is
the value of EF is 8
the answer part c) is
the value of FG is 15
