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.
To answer this question you need to create 2 equations:
S+C=50
2.50S+3.75C=3.35*(50)
S=50-C -so now you can plug in S into the second equation
2.50*(50-C)+3.75C=167.5
Now you just need to solve this equation, the final answer will be 34 pounds of colombian coffee and 16 pounds of sumatra coffee
Answer:
(-4,1)
Step-by-step explanation:
im pretty sure that is the answer, i will finish the test and tell you if it is right in the comments i guess lol
Answer:
22
Step-by-step explanation:
I did it on math class
The top one is the answer
