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3 years ago

Find the solution to the system of equations -3x-9y=18 4x+3y=12

Mathematics

1 answer:

chubhunter [2.5K]3 years ago

6 0

Answer:

(6,-4)

Step-by-step explanation:

-3x-9y = 18 (equation 1)

4x+3y = 12 (equation 2)

multiply equation 2 by 3, and add it to equation 2

-3x-9y = 18

12x+9y = 36

-----------------

X's cancel out

9x = 54

Divide both sides by 9

x = 6

Plug in 6 for x in any of the original equations

(Plugging into Equation 2)

4(6)+3y = 12 Multiply 4(6)

24+3y = 12 Subtract 24 from both sides

3y = -12 Divide 3 on both sides

y = -4

Therefore the solution is (6,-4).

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Answer:

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Step-by-step explanation:

Recall the following result:

The total surface area(S) of a regular pyramid is given by,

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Here, p represents the perimeter of the base , $l$ the slant height and B the base area of the pyramid.

From the given information:

Side of equilateral triangle = 20 inches

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Substitute the above values in equation (1) as shown below:

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