a²-3a-1=0,则a³-10a的值是______

a²-3a-1=0,则a³-10a的值是______
a²-3a-1=0,则a³-10a的值是______

a²-3a-1=0,则a³-10a的值是______
a²-3a-1=0,∴a²=3a+1
a³-10a = a(3a+1)-10a = 3a²+a-10a
=3(3a+1)-9a=9a+3-9a=3