Question

Barisan eritmetika U1=5 dan U6=55 tentukan suku ke-16

Answer 1

U6=55
U1=5
-------- (dikurangi)
5b = 50
b = 10.

a+b=5
a+10=5
a= -5

u16=a+(n-1)b
=-5+(16-1)10
= -5+(15 x 10)
= -5 + 150
=145.

Answer 2

5 = a
55 = a +5b
kurangi

-50 = -5 b
b = 10
a = 5

u16 = a + ( n-1 ) . b
5+(16-1).10
5+15.10
5+150
155