jika suatu barisan aritmatika mempunyai U1=48 dan U6=-32 maka U3*U5

a+ 5b = -32
48+5b= -32
5b= -80
b= -16

u3= a+2b = 58+ 2x -16 = 26
u5 = a+4b= 58+4x -16 = -6

Kelas 8 Matematika
Bab Barisan dan Deret Bilangan

b = (U6 - U1)/(6 - 1)
b = (-32 - 48)/5
b = -80/5
b = -16

U3 = U1 + 2b
U3 = 48 + 2 . (-16)
U3 = 48 - 32
U3 = 16

U5 = U6 - b
U5 = -32 - (-16)
U5 = -32 + 16
U5 = -16

U3 . U5
= 16 . (-16)
= -256