18 kg of 15% copper and 72 kg of 60% copper should be combined by the metalworker to create 90 kg of 51% copper alloy.
<u>Step-by-step explanation:</u>
Let x = kg of 15% copper alloy
Let y = kg of 60% copper alloy
Since we need to create 90 kg of alloy we know:
x + y = 90
51% of 90 kg = 45.9 kg of copper
So we're interested in creating 45.9 kg of copper
We need some amount of 15% copper and some amount of 60% copper to create 45.9 kg of copper:
0.15x + 0.60y = 45.9
but
x + y = 90
x= 90 - y
substituting that value in for x
0.15(90 - y) + 0.60y = 45.9
13.5 - 0.15y + 0.60y = 45.9
0.45y = 32.4
y = 72
Substituting this y value to solve for x gives:
x + y = 90
x= 90-72
x=18
Therefore, in order to create 90kg of 51% alloy, we'd need 18 kg of 15% copper and 72 kg of 60% copper.
Answer:
I believe you are correct
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Answer: The total number of colored papers is 18.
Step-by-step explanation:
Given: The ratio of coloured papers to wight papers is 3:8.
Let total number of colored papers = 3x
and total number of wight papers = 8x
Since, there are 48 wight papers , then


Now , number of colored papers = 3(6)=18
Hence, the total number of colored papers is 18.
Answer: C. A line that rises from left to right has a positive slope.
Step-by-step explanation: A. has a slope of 0, B. has an undefined slope, and D. is supposed to go left to right not right to left.
Answer:
1.6 OR 8/5
(They are the same thing.)