Помогите! Упростить выражения: а) 6/m^3+8+1/2m+m^2 б) 12/x^2+12x+36+12/x^2-36-1/x-6 в) 2x/x-1+3x+1/1-x^2-3/x+1

6 / (m^3+8) + 1/m (m+2) = (6m+m^2+4-2m) / m (m^3+8) = (m+2) ^2/m (m^3+8)

12 / (x+6) ^2+12 / (x^2-36) - 1 / (x-6) = (12x-12*6+12x+12*6-x^2-36-12x) / (x-6) (x+6) ^2=

= (x-6) ^2 / (6-x) (x+6) ^2 = (6-x) / (x+6) ^2

2x / (x-1) + (3x+1) / (1-x^2) - 3 / (x+1) = (-2x^2-2x+3x+1-3x+3) / (1-x^2) =

= (-2x^2-2x+4) / (1-x^2) = - 2 (x^2+x-2) / (1-x^2) = 2 (1-x) (x+2) / (1-x^2) = 2 (x+2) / (x+1)