Question

Giải hệ pt sau : 2x+y=4 và 5x-4y=3

Answer 1

`{(2x+y=4),(5x-4y=3):}`

`<=>{(y=4-2x),(5x-4(4-2x)=3):}`

`<=>{(y=4-2x),(13x=19):}`

`<=>{(y=14/13),(x=19/13):}`

Answer 2

`{(2x+y=4), (5x-4y=3):}`

`<=> {(8x + 4y = 16), (5x - 4y =3):}`

`<=> {(8x + 4y + 5x - 4y = 19), (2x + y=4):}`

`<=> {(13x = 19), (2x + y = 4):}`

`<=> {(x = 19/13), (y = 14/13):}`