dik u3=36,u5=81, tentukan u1
![]()
U3 = 36
U5 = 81
U1 = ?
U3 = U1 + b × (n - 1)
U3 = U1 + b × (3 - 1)
U3 = U1 + 2b
U5 = U1 + b × (n - 1)
U5 = U1 + b × (5 - 1)
U5 = U1 + 4b
U5 - U3 = (U1 + 4b) - (U1 + 2b)
81 - 36 = 4b - 2b
45 = 2b
b = 45/2
b = 22 1/2
U3 = U1 + 2b
36 = U1 + 2(22 1/2)
36 = U1 + 45
36 - 45 = U1
U1 = -9
[answer.2.content]
