I'll do one to give you a lead. You do the other ones:

\(\displaystyle 12m^3 y - 75my^3=3my(4m^2-25y^2)=3my(2m-5y)(2m+5y)\)

So first you factor out a common factor ( \(\displaystyle 3my\) ) , and then you use the formula for squares difference \(\displaystyle a^2-b^2=(a-b)(a+b)\) , with \(\displaystyle a=2m\,,\,\,b=5y\)