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3 years ago

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What is the answer to 20=5x 10y?

1 answer:

My name is Ann [436]3 years ago

5 0

I hope this helps you 5x=20 x=4 10x=10×4=40

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-2+0=? pleaseee help 10pointsss

Luba_88 [7]

-2 is the correct answer.

8 0

3 years ago

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How many pounds of a 15% copper alloy must be mixed with 700lb of a 30% copper alloy to maybe a 25.5% copper alloy

lisov135 [29]

Answer:

$300\; \rm lb$ .

Step-by-step explanation:

Let $x$ represent the mass (in pounds) of that $15\%$ copper alloy required, such that the final mixture would contain $25.5\%$ copper by mass.

Consider: if $x$ pounds of that $15\%$ copper alloy is mixed with $700$ pounds that $30\%$ copper alloy, what would be the mass of copper in the mixture?

Mass of copper in $x$ pounds of that $15\%$ copper alloy: $(0.15\, x)\; \rm lb$ .
Mass of copper in $700$ pounds of that $30\%$ copper alloy: $700 \times 0.30 = 210\; \rm lb$ .

Therefore, the mixture would contain $(210 + 0.15\, x) \; \rm lb$ of copper.

The mass of that mixture would be $(700 + x)\; \rm lb$ . The mass fraction of copper in that mixture would be:

$\displaystyle \frac{(210 + 0.15\, x)\; \rm lb}{(700 + x)\; \rm lb} \times 100\%$ .

This ratio is supposed to be equal to $25.5\%$ . These two pieces of equations combine to give an equation about $x$ :

$\displaystyle \frac{(210 + 0.15\, x)\; \rm lb}{(700 + x)\; \rm lb} \times 100\% = 25.5\%$ .

$\displaystyle \frac{210 + 0.15\, x}{700 + x} = 0.255$ .

Simplify and solve for $x$ :

$210 + 0.15\, x= 0.255\, (700 + x)$ .

$(0.255 - 0.15)\, x= 210 - 0.255 \times 700$ .

$\displaystyle x = \frac{210 - 0.255 \times 700}{0.255 - 0.15} = 300$ .

Therefore, $300\; \rm lb$ of that $15\%$ alloy would be required.

4 0

3 years ago

Maria estimates college tuition and fees, room and board, books, and other charges total $10,100. She will receive a scholarship

Olenka [21]

the answer is d.

10100-1100 is 9,000.

12 months× 4 years= 48 months

9,000÷48= 187.5

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3 years ago

Solve the equation for the unkown variable<br> 1) -1/x=-7/2+2/x

lakkis [162]

Hope this might help

6 0

2 years ago

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Which value of f 3f+5=32 a true statement

zhuklara [117]

Answer:

C. f = 9

Step-by-step explanation:

<u>→Subtract 5 from both sides:</u>

3f + 5 = 32

- 5 - 5

_________

3f = 27

<u>→Divide both sides by 3:</u>

f = 9

4 0

3 years ago