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What is the answer of this -x+3y=20 7y=x

User Trey Stout
by
7.4k points

1 Answer

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The answer of -x+3y=20; 7y=x will be x = -
(7)/(2\\) and y = -
(1)/(2).

Given,

-x+3y=20 .... (1)

7y=x .... (2)

By using the method of substitution.

We will use equation (2) as

7y=x

=>y=
(x)/(7) ....(3)

Putting equation (3) in (1)

We have, -x+3(
(x)/(7))=20

Taking L.CM.


(-7x+3x)/(7) = 20

-7x +3x = 140

-4x = 140

0r, x = -
(140)/(4)

x = -
(7)/(2)

Now by putting value of x in equation (2), we get

7y = x

7y = -
(7)/(2)

0r, y = -
(1)/(2)

Thus, x = -
(7)/(2\\) and y = -
(1)/(2)

User Csells
by
7.8k points

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