Question

Pada dret aritmetika diketahui U11=p+q dan U13=p. tentukan suku ke-5.

Answer 1

U11 = a + 10b = p+ q
u13= a + 12b =  p -
               -2b = q
b = -q/2

a + 12b = p
a  - 6q = p
a = p + 6q

u5 = a + 4b 
      = p + 6q + 4(-q/2)
      = p + 6q - 2q
     = p + 4q

Answer 2

U11 = a+ 10b = p + q
u13 = a+ 12b = p
________________-
-2b = q
b = -q/2
a=?
u13=a-12q/2=p
a - 6q = p
a = p + 6q


u5=a+4b
(p + 6q) + 4(q/-2)
(p + 6q) + 4q/-2
p + 6q - 4q/2
p - 12q/2 - 4q/2
p - 16q/2
p - 8q

u5= p - 8q