\[= \left( a^{\frac{1}{4}} - 1 \right)\left( a^{\frac{1}{4}} + 1 \right)\left( a^{\frac{1}{2}} + 1 \right) =\]
\[= \left( \left( a^{\frac{1}{4}} \right)^{2} - 1 \right)\left( a^{\frac{1}{2}} + 1 \right) =\]
\[= \left( a^{\frac{1}{2}} - 1 \right)\left( a^{\frac{1}{2}} + 1 \right) =\]
\[= \left( a^{\frac{1}{2}} \right)^{2} - 1 = a - 1\]
\[a = 51:\]
\[a = 51 - 1 = 50.\]