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5x=7y, X+7Y=21 how do u solve this by elemination​

1 Answer

6 votes

Answer:

The values are
x=(7)/(2) and
y=(5)/(2)

The solution is (
(7)/(2),
(5)/(2))

Explanation:

Given equations are
5x=7y\hfill (1) and


x+7y=21\hfill (2)

To solve the given equations by elimination method:

Equation (1) can be written as
5x-7y=0\hfill (3) and

Now multiply the equation (2) into 5 we get


5x+35y=105\hfill (4)

Subtracting equations (3) and (4) we get


5x-7y=0


5x+35y=105

_________________

-42y=-105


y=(105)/(42)

Therefore
y=(5)/(2)

Substitute the value
y=(5)/(2) in equation (1) we get


5x=7* (5)/(2)


5x=(35)/(2)


x=(35)/(2* 5)


x=(7)/(2)

Therefore
x=(7)/(2) and
y=(5)/(2)

The solution is (
(7)/(2),
(5)/(2))

User Meshtron
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