Question

докажите тоджество:
a^3+6a^2b+5ab^2/a^2+9ab+20b^2/a^2-2ab-3b^2/a^2+ab-12b^2=a

Answer 1

$frac{a(a+1)(a+5)}{(a+5)(a+4)}* frac{(a-3)(a+4)}{(a-3)(a+1)}=a$