Answer:
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Step-by-step explanation:
b is clearly negative
- - = +
so therefore, subtracting the negative will result in a larger answer than adding a small positive to a negative
Answer:
One Way Trip There = ($460.22)
There and Back Trip = ($465.26)
The operation between a rational and a irrational number that results in a rational number is a multiplication, hence the expression ab could represent a rational number.
<h3>What are rational and irrational numbers?</h3>
If a number can be represented by a fraction, it is rational, otherwise, it is irrational.
The addition/subtraction of a rational and an irrational numbers is irrational, while the multiplication is rational, hence the expression ab could represent a rational number.
More can be learned about rational numbers at brainly.com/question/10814303
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
Rewrite this symbolically: 6(2/6) = 12/6 = 2 (answer)
An equally good approach would be to cancel the 6's, obtaining 2 (answer)
