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.
B because there is only one negative and -63 divided by 7 equals -9. If it were -7 divided by 63 that would give you an answer in decimal form.
Answer: 24
Step-by-step explanation:
Answer:
y+3=-11/7(x-2)
Step-by-step explanation:
y-y1=m(x-x1)
m=(y2-y1)/(x2-x1)
m=(8-(-3))/(-5-2)
m=(8+3)/(-7)
m=11/-7
m=-11/7
y-(-3)=-11/7(x-2)
y+3=-11/7(x-2)
