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:
hrs =4
Step-by-step explanation:
550-11
200-x
cross multiply
550x=200×11
550÷550=2200÷560
x=4
Let's try the actual solution of the system
<span>y = –2x + 1
y = –2x – 3
Note that the slopes of the graphs of these two lines are the same: -2.
That means that the lines are parallel to one another.
Only the y-intercepts (1 and -3) are different.
Since the 2 lines never intersect, the system has no solution.
</span>
Answer:
.80
or
0.80
Step-by-step explanation:
80 is out of 100, which is other words is .80 or 0.80
Answer:
27?
Step-by-step explanation:
because 1 page per 1 hour leads up to 27 hours for 27 pages. Or if your not counting the 10 pages she has already written, she spent 17 hours.
