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:
C
Step-by-step explanation:
Angle CAD and angle BAD are congruent.
10x - 7 = 3x+ 7
10x - 3x = 7 + 7
7x = 14
(7x)/7 = 14/7
x = 2
Plug in x as 2.
10(2) - 7
20 - 7
= 13
Answer:
y greater than or equal to 14
Step-by-step explanation:
Given the inequality:
We solve it by isolating the variable y on one side. That is, in our case we add 27 to both sides and get:
Answer:
Three-fifths
Step-by-step explanation:
First, let us reduce 60% to its simplest form as shown below:
60% = 60/100 = 6/10 = 3/5
We see that 60% in its simplest for is 3/5. This is written as Three-fifths
