Answer: 490 grams of the first alloy should be used.
30 grams of the second alloy should be used.
Step-by-step explanation:
Let x represent the weight of the first alloy in grams that should be used.
Let y represent the weight of the second alloy in grams that should be used.
A chemist has two alloys, one of which is 15% gold and 20% lead. This means that the amount of gold and lead in the first alloy is
0.15x and 0.2x
The second alloy contains 30% gold and 50% lead. This means that the amount of gold and lead in the second alloy is
0.3y and 0.5y
If the alloy to be made contains 82.5 g of gold, it means that
0.15x + 0.3y = 82.5 - - - - - - - - - - - -1
The second alloy would also contain 113 g of lead. This means that
0.2x + 0.5y = 113 - - - - - - - - - - - - -2
Multiplying equation 1 by 0.2 and equation 2 by 0.15, it becomes
0.03x + 0.06y = 16.5
0.03x + 0.075y = 16.95
Subtracting, it becomes
- 0.015y = - 0.45
y = - 0.45/- 0.015
y = 30
Substituting y = 30 into equation 1, it becomes
0.15x + 0.3 × 30 = 82.5
0.15x + 9 = 82.5
0.15x = 82.5 - 9 = 73.5
x = 73.5/0.15
x = 490
Answer:
b.
It's too short. Write at least 20 characters to explain it well
(-1, 5) because if you plug in -1 to both equations, you should get 5 from both equations. They also cross at that point, making that the solution.
Nicki:x (12)
Claudia:x+5
Hunter:12
Decade=10 years
Dog: x-10
Philip:(x-10)+3=x-7
Sara: x-8
Sara:4
The values of the rates 4/5 mile in 8 minutes and 4 minutes to travel 2/5 mile are equal
<h3>How to compare and contrast the rates?</h3>
The rates are given as:
Rate 1 = 4/5 mile in 8 minutes
Rate 2 = 2/5 mile in 4 minutes
Calculate the above rates
This is done as follows:
Rate 1 = 1/10 mile per minute
Rate 2 =1/10 mile per minute
When the rates are calculated, the values are 1/10 mile per minute
Hence, the values of the rates 4/5 mile in 8 minutes and 4 minutes to travel 2/5 mile are equal
Read more about rate at:
brainly.com/question/2021001
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