geometrical progression?

Geometrical progression => (x/q;x;x*q), that is, the successor of a term is the term times a constant.

1° term = x / q (q = constant)

2° term = x

3° term = x * q

4º term = x * q * q = x * q^2

7° term = x * q^5

x + x * q = 9

x * q^5 = 8 * x * q^2

x * q^5 / (x * q^2) = 8

q^3 = 8

q = 2

x + x * q = 9

x + x * 2 = 9

3 x = 9

x = 3

5° = x * q^3 = x * 8 = 3*8 = 24.

a persevering with is a variety so as that there is not any n or the different variable invovled. Tn=2^(n+3) and changing n with the aid of (n-a million) provides Tn-a million = 2^(n+2). Tn/Tn-a million = 2^(n+3)/2^(n+2)=2^a million=2, it relatively is a persevering with considering that 2^p/2^q=26(p-q). So the form is geometric with undemanding ratio r=2. additionally the 1st term T1 =a=2^4=sixteen. b) locate S5 and S12 using Sn=a(r^n - a million)/(r-a million) = sixteen(2^n-a million) the mandatory sum is S12 - S5 which ought to offer 65024