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:7 quarters and 6 dimes
Step-by-step explanation:
Answer:
1/8 or .125
Step-by-step explanation:
There's only 8 sheets and 1 of them is green.
Answer:
What is the question?
Step-by-step explanation:
Answer:
y= -x-2
Step-by-step explanation:
y=ax+b
x= -2; y=0 => 0=-2a+b; b=2a
x= -1; y= -1 => -1=-a+b => b=a-1
2a=a-1=> a= -1; b= -2
=> y= -x-2
