1) (a-1)/(2*a+2)+(a+1)/(3-3*a)+(5*a-1)/(3*a^2-3) 2)(2*a+b)/(2*a^2-a*b)-(16*а)/(4*а^2-b^2)+(2*a-b)/(2*a^2+a*b) 3) (y^2-9)/(y^2-6y+9) 4) (b^2-4b+3)/(b^2-9) 5) (z^2-4z-21)/(z^2-6x-7)