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:
5.54 inches of rain
Step-by-step explanation:
Monday - 3.11
Tuesday - 0.81
Wednesday - 0.81 x 2= 1.62
3.11 + 0.81 + 1.62=5.54 inches
Answer:
Step-by-step explanation:3,9,27,81 because this is multiplication
Answer:
yup and yup
Step-by-step explanation:
also 1. is yup and yup
X-5y=36
x+y=-26
y=-26-x
x-5(-26-x)=36
x+130+x=36
2x+130=36
2x=36-130
2x=-94
x=47
