Hasil dari 105+101+97+…5+1 adalah
Jawaban Terkonfirmasi
Bab Barisan dan Deret
Matematika SMP Kelas IX
105 + 101 + 97 + …. + 1 = ?
a = 105
b = U2 – U1
b = 101 – 105
b = -4
Un = a + (n – 1) x b = 1
105 + (n – 1) x (-4) = 1
(n – 1) x (-4) = 1 – 105
n – 1 = -104/-4
n = 26 + 1
n = 27
Sn = (n/2) x (a + Un)
S27 = (27/2) x (105 + 1)
S27 = (27/2) x 106
S27 = 1.431