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:
Bus 1 is traveling faster.
Step-by-step explanation:
The information provided states that Bus 1 travels at 55 miles per hour. The graph shows that Bus 2 travels less than 50 miles per hour. This shows that Bus 1 travels more miles per hour.
Hope it helps!
Answer:
the value of x would be 5.5
Step-by-step explanation:
This is true by multiplying 2 by 5 and a half
Answer:
Below in bold.
Step-by-step explanation:
c) 3 x (9^2)^3/4 x ((81^3)^5/6
= 3 x 81^3/4 x 81^15/6
= 3 x 81^(3/4 + 15/6)
= 3 x 81^13/4
= 3 x 3^13
= 3^14
= 4,782,969.
f) (5x^-1y^2)^-2 / (25 x^2 y - 1)^2
= 5^-2 x^2y^-4 / 625 x^4y^-2
= 5^-2 x^-2 y^-2 / 5^4
= 5^-6 x^-2y^-2
= 0.000064x^-2y^-2.
