LCM of 245x6y5 and 49x5y2.
245=49×5; x6=x5×x; y5=y2×y3.
So all the components of the second expression divide into the corresponding components of the first, making the first expression the LCM:
245x6y5=5xy3×49x5y2.
(The HCF is the other expression because 49x5y2 divides into both expressions.)