The solution to this is 3(8)-3(9).
Answer:
tons of high steel and
tons of low steel
Step-by-step explanation:
Let x be the number of tons of high grade steel and y be the number of tons ow low grade steel needed.
In x tons of high grade steel there are
tons of iron
tons of magnese
In y tons of low grade steel there are
tons of iron
tons of magnese
NASA orders 500 tons of steel, so

and specifies that it must be in the proportion 80% iron and 20% magnese, so

From the first equation,

Substitute it into the second equation:

Answer:
The answer is A
Step-by-step explanation:
When you multiple the numerators across you get 39,283.2 not 39, 832. What this math problem is, is Dimensional Analysis. Its converting one unit of measurement to another
Another example:
Look at the attachment below.
812.30/83 = 9.78674698.....
Nearest tenth means one number under decimal place so...
812.30/83 ~ 9.8
Explanation: The 9.7... rounded up to 9.8 because the number after the tenths place (in this case the number after the 7) is greater or equal to 5.
You might want to see what other people say but I think that it is 40