Đáp án:
`(x,y)=(5/2,3/2),(-5/2,-3/2)`
Giải thích các bước giải:
`5x=3y`
`=>x=3/5y` thay vào `x^2-y^2=-4` ta có:
`(3/5y)^2-y^2=-4`
`=>9/25y^2-y^2=-4`
`=>-16/25y^2=-4`
`=>16/25y^2=4`
`=>y^2=25/4`
`=>` \(\left[ \begin{array}{l}y=\dfrac52\\y=-\dfrac52\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}\begin{cases}y=\dfrac52\\x=\dfrac35y=\dfrac32\\\end{cases}\\\begin{cases}y=-\dfrac52\\x=\dfrac35y=-\dfrac32\\\end{cases}\end{array} \right.\)
Vậy `(x,y)=(5/2,3/2),(-5/2,-3/2)`
