Вправи 101 - 200 » 170 (3-4)

3) (36/(x^2- 9) – (x-3)/(x+3) – (3+x)/(3-x)) : 6/(3-x) = –2. 1. 36/((x-3)(x+3)) – (x- 3^(\x-3))/(x+3) – (3+ x^(\x+3))/(3-x) = (36-(x-3)^2+ (x+3)^2)/((x-3)(x+3)) = (36-(x^2- 6x+9)+ (x^2+ 6x+9))/((x-3)(x+3)) = (36- x^2+ 6x-9+ x^2+ 6x+9)/((x+3)(x+3)) = (12x+36)/((x-3)(x+3)) = (12(x+3))/((x-3)(x+3)) = 12/(x-3); 2. 12/(x-3) • (3-x)/6 = (12(x-3))/((x-3) • 6) = –2; 4) ((2y-1)/(y^2+ 2y+4) + (9y+6)/(y^3- 8) + 1/(y-2)) • (y^2- 4)/18 = (y+2)/6. 1. (2y- 1^(\y-2))/(y^2+ 2y+4) + (9y+6)/((y-2)(y^2+ 2y+4)) + 1^(\y^2+2y+4)/(y-2) = ((y-2)(2y-1)+ 9y+6+(y^2+ 2y+4))/((y-2)(y^2+ 2y+4)) = (2y^2- y-4y+2+9y+6+ y^2+ 2y+4)/((y-2)(y^2+ 2y+4)) = (3y^2+ 6y+12)/((y-2)(y^2+ 2y+4)) = (3y^2+ 6y+12)/((y-2)(y^2+ 2y+4)) = (3(y^2+ 2y+4))/((y-2)(y^2+ 2y+4)) = 3/(y-2); 2. 3/(y-2) • ((y-2)(y+2))/18 = (y+2)/6.