Question

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

Answer 1

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)`)