Respuesta :

the answer is 4/3 or -4/3

Answer:

4/3

Step-by-step explanation:

a2 = 324 and a4 = 36

second term is 324  and fourth term is 36

[tex]a_n= a_1(r)^{n-1}[/tex]

To get second term, replace n with 2

[tex]a_2= a_1(r)^{2-1}[/tex]

[tex]a_2= a_1(r)[/tex]

replace a2 with 324

[tex]324= a_1(r)[/tex] -----------> equation 1

To get fourth term , replace n with 4

[tex]a_4= a_1(r)^{4-1}[/tex]

[tex]a_4= a_1(r)^3[/tex]      

Replace the value

[tex]36= a_1(r)[/tex]  -----------> equation 2

divide second equation by first equation

[tex]36= a_1(r)^3[/tex]    divide by [tex]324= a_1(r)[/tex]

1/9 = r^2

take square root on both sides

1/3= r

now we find a1

[tex]324= a_1(r)[/tex]  

[tex]324= a_1(\frac{1}{3})[/tex]

multiply by 3 on both sides

972= a_1

So a1= 972,  r= 1/3

now find out 7 term by replacing 'n' with 7

[tex]a_7= 972(\frac{1}{3})^{7-1}[/tex]

So 7th term is 4/3