The 8th term of a g.p is -7/32 fine it's common ration if its first term is 28

Answer 1

term 1 = a = 28
term 2 = a r
term 3 = a r^2

term 8 = a r^7 = -7/32

28 r^7 = -7/32

r^7 = -1/(4*32)

r^7 = -1/2^7

r = -1/2

Answer 2

DAT NOT THE EXAMPLE GIVEN TO US THE FORMULAR IS DIFFERENT