Х+2 х+3 х+5 развязать уровнение + + х-1. х+1. - вопрос №27541332351112 от Gllodory 24.01.2020 15:13

Question

Алгебра: Х+2 х+3 х+5 развязать уровнение + + х-1. х+1. 1-х2

Gllodory · Answer

(x+2) / (x-1) + (x+3) / (x+1) + (x+5) / (1-x^2) = (x+2)*(x+1) / (x-1)(x+1) + (x+3)*(x-1) / (x+1)(x-1) - (x+5) / (x^2-1) = (x^2+3x+2) + (x^2+2x-3) - (x+5) / (x-1)(x+1) = 2x^2+6x+4 / (x-1)(x+1) = (x+1)(x+2) / (x-1)(x+1) = x+2 / x-1

2x^2+6x+4 = 0
D = 3^2 - 4*1*2 = 9 - 8 = 1
x1 = (-3-1) / 2 = -4 / 2 = -2
x2 = (-3+1) / 2 = -2 / 2 = -1
(x - x1)*(x - x2) = (x - (-2))*(x - (-1)) = (x+1)*(x+2)