Diket: U3= -11 U7=-39 Ditanya: U30=...?

U3 = -11 = U1 +2b =-11
U7 = -39 = U1 + 6b =-39
Dikurangkan
Menjadi 4b=28
Maka b =7

U1 = U1 +2b = -11
U1 = -14 -11 =-25

U30 = U1+ 29b
-25 + 29(7)
=178

U3 => a+2b =-11
U7=> a+6b = -39
------------------- -
-4b = 28
b = -7
a+2b =-11
a + 2 (-7) = -11
a -14 = -11
a = -11 +14
a = 3

U30 = a+29b
= 3 + 29 (-7)
= 3 -203
=- 200