A) 3a³b - 12a²b + 6ab = 3ab*(a² - 4a + 2)
б) x (x - 1) + 2 (x - 1) = (x - 1)(x + 2)
а) xy + 3y + xz + 3z = (xy + 3y) + (xz + 3z) = y*(x + 3) + z*(x + 3) = (x + 3)(y + z)
б) 25 - с² = (5 - c)(5 + c)
в) ab² - 2abc + ac² = a*(b² - 2bc + c²) = a*(b - c)²
x² - xy
———— =
x² - y²
x*(x - y)
---------------- = (сокращаем (х - у) в числителе и знаменателе) =
(x - y)(x + y)
х
-------
х + у
(a - 2) (a + 2) - a (a - 1) = a² - 4 - a² + a = -4 + a
a) (2x + 8)² = 0, x ≠ 4
4x² + 32x + 64 = 0
a = 4, b = 32, c = 64
по т. Виета:
x1 + x2 = -b/a = -32/4 = -8
x1*x2 = c/a = 64/4 = 16
16 = (-4)*(-4)
-8 = -4 + (-4)
x1 = -4, x2 = -4
б) x² - 4x = 0
x*(x - 4) = 0
x = 0 или x - 4 = 0
x = 0, x = 4