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:
x=17/4
Step-by-step explanation:
(x-3)/(x+2)=1/5
cross product
1(x+2)=5(x-3)
x+2=5x-15
5x-x-15=2
4x-15=2
4x=2+15
4x=17
x=17/4
Answer:
185/24
Step-by-step explanation:
Convert both to fractions with the same denominator first.
35/8= 105/24
10/3= 80/24
105/24+80/24
= 185/24
Hello from MrBillDoesMath!
Answer:
7/3 and 14/3 inches
Discussion:
Let P1 = "Piece 1" and "P2 = Piece 2", Then P2 = 2 * P1 and
P1 + P2 = 7 => as P2 = 2 P1
P1 + 2P1 = 7 =>
3P1 = 7 => divide both sides by 7
P1 = 7/3
Then P2 = 2 P1 - 2* (7/3) = 14/3
Thank you,
MrB
Answer: No, it can never be greater. At most it can be equal though.