Вправа 644 алгебра Бевз гдз 7 клас
№ 644
а) х3 + 2х2 – х = 2
x2(x + 2) – (x + 2) = 0
(x + 2)(x2 – 1) = 0
(x + 2)(x – 1)(x + 1) = 0
x1 = –2; x2 = 1; x3 = –1;
б) у3 – 3у2 + 4у = 12
y2(y – 3) – 4(y – 3) = 0
(y – 3)(y2 – 4) = 0
(y – 3)(y – 2)(y + 2) = 0
y1 = 3; y2 = 2; y3 = –2;
в) х2(х – 3) + 2х(х – 3) + х – 3 = 0
(x – 3)(x2 + 2x + 1) = 0
(x – 3)(x + 1)2 = 0
x1 = 3; x2 = –1;
г) х2(х2 – 4х + 4) – 9(х2 – 4х + 4) = 0
(x2 – 4x + 4)(x2 – 9) = 0
(x – 2)2(x – 3)(x + 3) = 0
x1 = 2; x2 = 3; x3 = –3.
вправи поруч
