Question

If the third term,sixth term and last term of a gp are 6, 48 and 3072. find the first term and the number of terms in the g.p​

Answer 1

Step-by-step explanation:

t3=6

t6=48

tn=3072

tn=a+(n-1)×d

t3=a+(3-1)d

6=a+2d........(1)

t6=a+(6-1)d

48=a+5d.......(2)

subtracting 1and 2

a+2d=6

-

a+5d=48

.....................

-3d=-42

d=14

put d=14 in equation 1

a+2d=6

a+2(14)=6

a+28=6

a=6-28

=-22

so 1st term is -22