Ask the master to solve the math problem "If A6 = 6 and A9 = 9 in the geometric series an, what is a3?" ? I listed a set of unary quadratic equations in the series of three times calculating Q ratio. ... 1 There is no need to calculate q, that is, the square of a6 is equal to a9Xa3 and a3=4 is equal to 4 (the sum of subscripts is required to be equal).

These three numbers are 2, 4 and 8 respectively. Because the numerical value is small, you can take a special value and then quickly verify the answer.

Because a 1Xa4=a2Xa3, a2Xa3= 1/4, and because a2+a3= radical number 2,

Find a2= (radical number 2- 1)/2, a3= (radical number 2+ 1)/2, then Q equals a3/a2=3+2 radical number 2.

4a5/A2 = the cube of q =-1/8, and q=- 1/2 is obtained.

Then a 1=-8, an = (n- 1 power) of a1xq =- 1/2{(n-4) power}

A3Xa4Xa5=a4 Cube =8, find a4=2.

A2A3A4A5A6 = the fifth power of A4 =32

Hope to adopt, thank you.