seutas tali dipotong jadi 6 geometri teependek 30 terpanjang 960 panjangn tali semula=...cm

U6=30*r^5=960
r^5=32
r=2
S6=30(2^6-1)/(2-1)
=30(64-1)
=30*63
=1890

Dik:
a = 30 -------->> (1)

U6 = 960
a.r⁵ = 960 --->> (2)

Dit:
S6 = ....... ?

Jwb:
Subtitusikan 1 ke 2,,
a.r⁵ = 960
30.r⁵ = 960
r⁵ = 960/30
r⁵ = 32
r = 2

Jadi,
Sn = [a(rⁿ - 1)]/[r - 1]
S6 = [30(2⁶ - 1)]/[2 - 1]
S6 = [30(64 - 1)]/1
S6 = 30(63)
S6 = 1890

Jadi, panjang tali semula adalah 1890 cm