A rombus
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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.
First, we need to get rid of the denominator. to do so, we will simply multiply all terms by 12 (which is the result of 3*4).
(3x/4)(12)+(2/3)(12)=(x/3)(12)
9x + 8 = 4x
then we will separate the variable in one side and solve to get its value
9x-4x = -8
5x = -8
x = -8/5
Answer:
4 she lost 4 pounds, how do u not know this dood
Step-by-step explanation: