v2-4v-21/3v2+6v * v2+8v/v2+11+24

write your type of questions this way :

(v2-4v-21)/(3v2+6v)(v2+8v)/(v2+11+24)

= (v-7)(v+3)/[3v(v+2)](v)(v+8)/[(v+3)(v+8)]
= (v-7)/[v(v+2)]