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:
The length of AC is 10 units
Step-by-step explanation:
In the given circle O
∵ AOCB is a rectangle
∵ OB and AC are the diagonals of the rectangle AOCB
∵ Diagonals of the rectangle are equal in lengths
→ That means OB and AC are equal in lengths
∴ OB = AC
∵ O is the center of the circle
∵ B is a point on the circle
∴ OB is a radius of the circle O
∵ The radius of the circle is 10 units
∴ OB = 10 units
∵ OB = AC
∴ AC = 10 units
∴ The length of AC is 10 units
Answer:
132,000
Step-by-step explanation:
Answer:
-3/5
Step-by-step explanation:
I was always taught rise over run. count how many units up/down the next point is and how many units over.
