We can rewrite the expression as:
#3/1 -: 129/1 => (3/10)/(129/1)#
Now, we can use this rule for dividing fractions to evaluate the expression:
#(color(red)(a)/color(blue)(b))/(color(green)(c)/color(purple)(d)) = (color(red)(a) xx color(purple)(d))/(color(blue)(b) xx color(green)(c))#
#(color(red)(3)/color(blue)(10))/(color(green)(129)/color(purple)(1)) =>#
#(color(red)(3) xx color(purple)(1))/(color(blue)(10) xx color(green)(129)) =>#
#(cancel(color(red)(3))color(red)(1) xx color(purple)(1))/(color(blue)(10) xx cancel(color(green)(129))color(green)(43)) =>#
#1/430#