Question

Tlong jawab yg ini jga ya :) ksih jalan.mksih bnyak

Answer 1

Buat beberapa variabel untuk barisan geometri:
y = U₂ - U₄
y = ar - ar³
y = ar(1 - r²)

Serta:
x = U₃ - U₆
x = ar² - ar⁵
x = ar²(1 - r³)

Sehingga:
x/y = [ar²(1-r³)]/[ar(1-r²)]
x/y = r(1-r³)/(1-r²)
Ingat pemfaktoran:
x/y = r[(1-r)(1+r+r²)]/[(1+r)(1-r)]
x/y = r(1+r+r²)/(1+r)
x/y = (r³+r²+r)/(r+1) [C]

Answer 2

Diketahui : x = U₃ - U₆ dan y = U₂ - U₄

x = U₃ - U₆
x = ar² - ar⁵
x = ar²(1 - r³) ............. (1)

y = U₂ - U₄
y = ar - ar³
y = ar(1 - r²) ................ (2)

Ditanyakan dalam soal x/y, maka:
x/y = {ar²(1-r³)}/{ar(1-r²)}
x/y = r(1-r³)/(1-r²)
x/y = r{(1-r)(1+r+r²)}/{(1+r)(1-r)}
x/y = r(1+r+r²)/(1+r)
x/y = (r³+r²+r)/(r+1)

Jawaban : C