x/7-1/2=1/y+3 tìm x,y ui 7 phút nhé vote 5 sao cho à

Đáp án:

`x/7 - 1/2 = 1 / ( y + 3 )`

`<=>` `( 2x - 7 ) / 14 = 1 / ( y + 3 )`

`<=>` `( 2x - 7 ) ( y + 3 ) = 14 . 1 = 14`

$\bullet$ `{(2x - 7 = 7),(y + 3 = 2):}`

`<=>` `{(2x = 14),(y = -1):}`

`<=>` `{(x = 7),(y = -1):}`

$\bullet$ `{(2x - 7 = 2),(y + 3 = 7):}`

`<=>` `{(2x = 9),(y = 4):}`

`<=>` `{(x = 9/2),(y = 4):}`

$\bullet$ `{(2x - 7 = -1),(y + 3 = -14):}`

`<=>` `{(2x = 6),(y = -17):}`

`<=>` `{(x = 3),(y = -17):}`

$\bullet$ `{(2x - 7 = -14),(y + 3 = -1):}`

`<=>` `{(2x = -7),(y = -4):}`

`<=>` `{(x = -7/2),(y = -4):}`

$\bullet$ `{(2x - 7 = 1),(y + 3 = 14):}`

`<=>` `{(2x = 8),(y = 11):}`

`<=>` `{(x = 4),(y = 11):}`

$\bullet$ `{(2x - 7 = 14),(y + 3 = 1):}`

`<=>` `{(2x = 21),(y = -2):}`

`<=>` `{(x = 21/2),(y = -2):}`

Vậy `:`

`( x ; y ) = ( 7 ; -1 ) ; ( 9/2 ; 4 ) ; ( 3 ; -17 ) ; ( -7/2 ; -4 ) ; ( 4 ; 11 ) ; ( 21/2 ; -2 )`