Deret aritmatika dengan a=-2 un=37 dan sn=210 cari n

a = -2
un= 37
Sn = 210

Jawaban

Sn = (n/2) (a + Un)
210 = n/2 (-2 + 37)
210/2 = 35n
105 = 35n

n = 105/35
n = 3