А) 3х + 2 =11 3х = 11 – 2 3х = 9 х = 9 : 3. х = 3 Ответ: х = 3. Б) 5(х – 3) + 2 = 3 (х – 4) + 2х ‒ 1 5х – 15 + 2 = 3х – 12 + 2х ‒ 1 5х – 3х ‒ 2х = – 12 ‒ 1 + 15 ‒ 2. 0х = 0. Ответ: х - любое число. В) х + 8 = х + 5. х – х = 5 ‒ 8. 0х = ‒ 3. Ответ: нет решений. | А) a2 - 12a = 0. a2 - 12a = 0 | a(a - 12) = 0 | a1 = 0 | a - 12 = 0 | | a2 = 12 | | | Б) 24 = 2y2. 24 = 2y2 | 24 - 2y2 = 0 | -2y2 = -24 | y2 = 12 | y1 = +√12 | y2 = -√12 | В) 7x2 = x. 7x2 = x | 7x2 - x = 0 | x(7x - 1) = 0 | | 3х2 – 7х +4=0 5х2 – 8х +3=0 3х2 – 13х +14=0 2у2 – 9у +10=0 5у2 – 6у +1=0 4х2 +х – 33=0 у2 – 10у – 24=0 р2 + р – 90=0 14х2 – 5х – 1=0 | x4 - 10x2 + 9 = 0. Заменяем x2 на y y2 - 10y + 9 = 0. D = b2 - 4ac = (-10)2 - 4 · 1 · 9 = 100 - 36 = 64, D 0. y1 = (10 + 8) : 2 = 9, y2 = (10 - 8) : 2 = 1. x2 = 9 и x2 = 1. 1) x2 = 9; x1 = 3, x2 = -3; 2) x2 = 1; x3 = 1, x4 = -1. Ответ: 3, -3, 1, -1. | х3 – 5 х2 + 8 х – 4 = 0 х3 – 2 х2 –3 х2 + 8х – 4 = 0 х2 (х – 2) – (3 х2 – 8х + 4) = 0 3 х2 – 8х + 4 = 0 х = 2 х = 2/3 х2 (х – 2) – (3 (х –2) (х – 2/3)) = 0 х2 (х – 2) – ((х – 2) (3х – 2)) = 0 (х – 2)(х2 – 3х + 2) = 0 х – 2 = 0 х2 – 3х + 2 = 0 Ответ: х = 2 х = 2 х = 1 | (2) : | 1. ; 2. ; 3. ; 4. ; 5. ; 6. ; 7. ; 8. ; 9. ; 10. ; 11. ; 12. ; 13. ; 14. ; 15. |