hitunglah 1 + 2 + 3 + 4 + ... + 49 =
Matematika
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Pertanyaan
hitunglah 1 + 2 + 3 + 4 + ... + 49 =
2 Jawaban
-
1. Jawaban ArZain
Diketahui:
a = 1
b = 2 - 1 = 1
Pembahasan:
Un = a + (n - 1)b
49 = 1 + (n - 1)1
49 = 1 + n - 1
n = 49
Maka,
Sn = n/2(2a + (n-1)b)
S49 = 49/2(2.1 + (49-1)1)
S49 = 49/2(2 + 48)
S49 = 49/2(50)
S49 = 49(25)
S49 = 1225 -
2. Jawaban Ridafahmi
n = 49
a = 1
Un = 49
Sn = n/2 × (a + Un)
S49 = 49/2 × (1 + 49)
S49 = 49/2 × 50
S49 = 1225