\[\left( 49^{\frac{1}{4}} - 25^{\frac{1}{4}} \right)\left( 49^{\frac{1}{4}} + 25^{\frac{1}{4}} \right) =\]
\[= \left( 49^{\frac{1}{4}} \right)^{2} - \left( 25^{\frac{1}{4}} \right)^{2} =\]
\[= \left( 7^{2} \right)^{\frac{1}{2}} - \left( 5^{2} \right)^{\frac{1}{2}} = 7 - 5 = 2\]