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:
A
Step-by-step explanation:
Step 1: Simplify both sides of the inequality.
−y+4≥8
Step 2: Subtract 4 from both sides.
−y+4−4≥8−4
−y≥4
Step 3: Divide both sides by -1.
−y
−1
≥
4
−1
y≤−4
Answer: (v + 7)(v -3)
Step-by-step explanation:
(v +7)(v -3)
v x v = v^2
v x -3 = -3v
7 x v = 7v
7 x -3 = -21
v^2 -3v +7v -21 = v^2 +4v -21 = 0
Answer:
Yes
Step-by-step explanation:
A function is a function when each domain is paired with exactly 1 range. So, this also means that there can't be a domain with more than 1 of the same number. Meaning 2 3's or 4 2's.
I am also confused, It is so hard
