U,9 = 35 dan U,3 = 45 tentukan: a,b,Un U25
Matematika
gustipradita
Pertanyaan
U,9 = 35 dan U,3 = 45
tentukan: a,b,Un
U25
tentukan: a,b,Un
U25
1 Jawaban
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1. Jawaban afrians94
U9 = 35
U3 = 45
b = U9 - U3 / 9 - 3
b = 35 - 45 / 6
b = -10/6 = -5/3
a = U1
b = U3 - a / 3 - 1
b = 45 - a / 2
-5/3 = 45 - a / 2
-10/3 = 45 - a
a = 45 + 10/3
a = 145/3
Un = a + (n - 1)b
= 145/3 + (n - 1) (-5/3)
= 145/3 - 5n/3 + 5/3
= 150/3 - 5n/3
= 5 - 5n/3
U25 = 5 - 5.25/3
= 5 - 125/3
= -110/3