a2a6=9
a 1^2 * q^6=9
4a3+a5+a3a5
=4a 1q^2+a 1q^4+9
& gt= 2 (4 * a1q 2 * a1* q 4)+9 under the radical sign.
=2*6+9
=2 1
17
a = -3
x^2-3>； 0
{x|- root number 3