a - 9*a^(1/2) a^(1/2) * (a^(1/4) - 3) * (a^(1/4) + 3)
= =
7 * a^(1/4) + 21 7 * (a^(1/4) + 3)
a^(1/2) * (a^(1/4) - 3)
7
a - 9*a^(1/2) a^(1/2) * (a^(1/4) - 3) * (a^(1/4) + 3)
= =
7 * a^(1/4) + 21 7 * (a^(1/4) + 3)
a^(1/2) * (a^(1/4) - 3)
7