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3 years ago

Solve by substitution -x+y=7 and 2x+3y=31

Mathematics

1 answer:

Rzqust [24]3 years ago

7 0

Answer:

(2,9)

Step-by-step explanation:

To do this you have to solve one of the equations for a variable.

-x+y=7

2x+3y=31

Because the first equation doesn't have any numbers attached to the variables I decided to solve for the y in that equation.

-x+y=7

y=x+7

With this now one would have to plug this into the second equations:

2x+3(x+7)=31

Use the distributive property.

2x+3x+21=31

simplify.

5x+21=31

Isolate the x.

-21 -21

5x=10

solve for the x.

x=2

Plug the x into one of the equations and solve for y.

-x+y=7

-2+y=7

isolate the y.

+2 +2

y=9

This is the point of solution.

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A farmer divided his piece of land into 2 equivalent groups and the quality of the soil is the same in both of these groups. He

Dimas [21]

Answer:

Observational would mean that he (farmer) has no direct impact or change on the statistical study.
Experiment would mean that he imposed a certain treatment up a group in this case it would be the land.
Hence we can determine that the the study was an experimental one.

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2 years ago

What is this number in standard form? <br> (8×100)+(4×1)+(6×1100)+(3×11,000)

Korvikt [17]

Answer:

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Step-by-step explanation:

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2 years ago

Read 2 more answers

The cost of 3 notebooks and 2 pencils is $5.10. At the same prices, the cost of 2 notebooks and 3 pencils is $4.65. What is the

Pepsi [2]

Answer:

$1.95

Step-by-step explanation:

notebook = n

pencil = p

3n + 2p = 5.10

2n + 3p = 4.65

multiply top equation by 2 and bottom by 3

6n + 4p = 10.20

6n +9p = 13.95

subtract bottom equation from the top equation

-5p = -3.75

divide by 5, negatives cancel out

p = 0.75

sub p into either equation, I chose the original top equation

3n + 2(0.75) = 5.10

3n + 1.50 = 5.10

subtract 1.50 from both sides

3n = 3.60

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2 years ago

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2 years ago

The gross weight of a truck containing 30 pigs is 8 tons 1,123 pounds and 6 ounces. The average weight of one pig is 95 pounds 1

irakobra [83]

Answer: The net weight of the pigs of the truck is 1 ton 868 pounds 12 ounces.

The weight of the empty truck is 7 tons 254 pounds 10 ounces.

Step-by-step explanation:

Since we have given that

The gross weight of a truck containing 30 pigs = 8 tons 1123 pounds 6 ounces

Average weight of one pig = 95 pounds 10 ounces

Now,

We know that

$1\text{ pound}=16\text{ ounces}$

So,

$\text{Gross weight of truck containing 30 pigs}\\=8\text{ tones }1123\times 16+6\text{ ounces}\\=8\text{ tons }17974\text{ ounces}$

Similarly,

$\text{ average weight of one pig }\\=95\times 16+10\text{ ounces}\\=1530\text{ ounces}$

So, Net weight of the pigs in the truck

$1530\times 30\\ =45900\text{ ounces}\\\\=\frac{45900}{16}\\\\=2868\text{ pounds }12\text{ ounces}\\\\=1\text{ ton }868\text{ pounds }12\text{ ounces }$

So, the net weight of the pigs of the truck is 1 ton 868 pounds 12 ounces.

Now, we'll find the weight of the empty truck is given by

$\text{Gross weight of a truck containing} -\text{ Net weight of pigs in the truck}\\=8\text{ tons}1123\text{ pounds}6\text{ ounces}-1\text{ton }868\text{ pounds }12\text{ounces}\\=(8\times 2000\times 16+1123\times 16+6)-(1\times 2000\times 16+868\times 16-12)\\=273974\text{ ounces}-45900\text{ ounces}\\=228074\text{ounces }\\=7\text{ tons }254\text{ pounds }10\text{ ounces}$

Hence, the weight of the empty truck is 7 tons 254 pounds 10 ounces .

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2 years ago