Question 303260
z^2+17z+72/z^2+18z+81  Devide  z^2+8z/z^2+15z+54

={{{(z^2+17z+72)/(z^2+18z+81)}}}÷{{{(z^2 + 8z)/(z^2+15z+54)}}}

={{{(z+9)(z+8)/(z+9)(z+9)}}}÷{{{(z(z+8))/(z+9)(z+6))}}}


={{{(z+9)(z+8)/(z+9)(z+9)}}}*{{{(z+9)(z+6)/(z(z+8))}}}

Cancel out (z+9),(z+8)

={{{(z+6)/(z)}}}