Question

Find a pair of numbers there is a member of both 6X plus Y equals 20 and X equals 2Y -1

Answer 1

The pair of number is x=3 and y = 2

Explanation:

Given:

6X plus Y equals 20

X equals 2Y -1

To Find:

The number X and Y

Solution:

6X plus Y equals 20 can be written as

`6x+y =20`------------------(1)

X equals 2Y -1 can be written as

`x =2y-1`

`x -2y = -1`-------------------(2)

Now lets solve equation (1) and (2)

multilply
`6x+y =20` by 2 , we get

`12x+2y =40`-------------------(3)

Adding (2) and (3)

`x -2y = -1`

`12x+2y =40`

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`13x =39`

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`x =(39)/(13)`

x =3

Substitute x = 3 in eq(2)

`3-2y = -1`

`-2y = -1-3`

`-2y = -4`

`y = (-4)/(-2)`

y = 2