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3 years ago

[15 Points, Just check for equation]

Mathematics

1 answer:

tatuchka [14]3 years ago

3 0

Answer:

No; 0.075(15 + s) = 3; s = 25 oz

Step-by-step explanation:

No, but <em>you are close</em>.

The mass of copper in your 800 grade silver is

Mass = 0.20 × 15 = 3 oz

You are adding s oz of silver so that 7.5 % of the total mass is still 3 oz of copper.

The equation becomes

0.075(15 + s) = 3 Divide both sides by 0.075

15 + s = 40 Subtract 15 from each side

s = 25 oz

You add 25 oz of silver to your 800 grade alloy to get sterling .

<em>Check: </em>

0.075(15 + 25) = 3

0.075 × 40 = 3

3 = 3

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Now we will solve this expression with the help of law of exponents.

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$2^{\frac{2}{9}}\times 3^{-\frac{2}{3} }=(\sqrt[9]{2})^2\times (\sqrt[3]{\frac{1}{3} } )^2$ [Option 1]

$2^{\frac{2}{9}}\times 3^{-\frac{2}{3} }=(\sqrt[9]{2})^2\times (\sqrt[3]{\frac{1}{3} } )^2$

$=(2^2)^{\frac{1}{9}}\times (3^2)^{-\frac{1}{3} }$

$=\sqrt[9]{4}\times \sqrt[3]{\frac{1}{9} }$ [Option 3]

$2^{\frac{2}{9}}\times 3^{-\frac{2}{3} }=(2^2)^{\frac{1}{9}}\times (3^{-2})^{\frac{1}{3} }$

$=\sqrt[9]{2^2}\times \sqrt[3]{3^{-2}}$ [Option 7]

Therefore, Options (1), (2), (3) and (7) are the correct options.

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