Tìm `x`:
`y^2 + 2y - 7x - 12 = 0`
`⇔ 2y − 7x − 12 = −y^2`
`⇔ −7x − 12 = −y^2 −2y`
`⇔ −7x = −y^2 − 2y + 12`
`⇔ (-7x)/(-7) = (12 - 2y - y^2)/(-7)`
`x = (12 - 2y - y^2)`
`x = (y^2 + 2y - 12)/(7)`
Tìm `y` (bù bình phương):
`y^2 + 2y - 7x - 12 = 0`
`⇔ y^2 + 2y − 7x − 12 = 0`
`⇔ y^2 + 2y − 7x − 12 − (−7x − 12) = −(−7x − 12)`
`⇔ y^2 + 2y = −(−7x − 12)`
`⇔ y^2 + 2y = 7x + 12`
`⇔ y^2 + 2y + 1^2 = 7x + 12 + 1^2`
`⇔ y^2 + 2y + 1 = 7x + 12 + 1`
`⇔ y^2 + 2y + 1 = 7x + 13`
`⇔ (y + 1)^2 = 7x + 13`
`⇔` $\sqrt{(y + 1)^2}$ `=` $\sqrt{7x + 13}$
`⇔ y + 1 =` $\sqrt{7x + 13}$
`⇔ y + 1 = -` $\sqrt{7x + 13}$
`y =` $\sqrt{7x + 13}$ `- 1`
`y = -` $\sqrt{7x + 13}$ `- 1`
Cho mình xin hay nhất nha bạn!!!!
@Drew Mclntyre
