(6x^2+18x^4)/(12x^3)=(6x^2(1+3x^2))/ (12x^3)=( 1+3x^2) /2x
(25y^(2)-4)/(25y+10)=((5y-2)(5y+2))/(5(5y+2)) =(5y-2)/2
(9-a^(2))/a^(2)+6a+9=((3-a)(3+a)) / ((3+a)(3+a)) =(3-a)/(3+a)
(6x^2+18x^4)/(12x^3)=(6x^2(1+3x^2))/ (12x^3)=( 1+3x^2) /2x
(25y^(2)-4)/(25y+10)=((5y-2)(5y+2))/(5(5y+2)) =(5y-2)/2
(9-a^(2))/a^(2)+6a+9=((3-a)(3+a)) / ((3+a)(3+a)) =(3-a)/(3+a)