Задачі і вправи для повторення » 45 (2)

2) y = (〖3x〗^2+ 2x-1)/(x+1) = ((3x-1)(x+1))/(x+1) = 3x – 1. ОДЗ: x ≠ –1 3x2 + 2x – 1 = 3(x – 1/3)(x + 1) = (3x – 1)(x + 1). D = 22 – 4 • 3 • (–1) = 4 + 12 = 16; x1 = (-2- √16)/(2 •3) = (-6-4)/6 = (-6)/6 = –1; x2 = (-2+ √16)/(2 • 3) = (-2+4)/6 = 2/6 = 1/3.