1) 3ab-15a+12b-60= 3a(b-5)+12(b-5)=(3a+12)(b-5)=3(a+4)(b-5)
2)a^4-625= (a²-25)(a²+25)=(a-5)(a+5)(a²+25)
1) 3ab-15a+12b-60= 3a(b-5)+12(b-5)=(3a+12)(b-5)=3(a+4)(b-5)
2)a^4-625= (a²-25)(a²+25)=(a-5)(a+5)(a²+25)