Đáp án:
`a) x = -36`
`b) x =` -`1989/11`
`c) x = 24`
`d) x = 78`
Giải thích các bước giải:
`a) (x - 1)(x + 1) - x(x + 1) = 35`
`⇒ (x - 1 - x)(x + 1) = 35`
`⇔ -x - 1 = 35`
`⇔ x = -36`
`b) (2x - 5)(x - 3) = 2x² + 2004 `
`⇔ 2x² - 6x - 5x + 15 = 2x² + 2004`
`⇔ -11x = 1989 `
`⇔ x =` `-1989/11`
`c) (x + 2)(x + 4) - x(x + 2) = 104`
`⇔ (x + 2)(x + 4 - x) = 104`
`⇔ 4x + 8 = 104`
`⇔ 4x = 96`
`⇔ x = 24 `
`d) (x - 1)(x + 4) - x(x - 1) = 308`
`⇔ (x - 1)(x + 4 - x) = 308`
`⇔ 4x - 4 = 308`
`⇔ 4x = 312 `
`⇔ x = 78`
