Question

No.19 mohon bantuan nya

Answer 1

Suku ke 5 = a + 4d
suku ke 8 = a+7d
a + 4d + a + 7d = 2a +11 d
2a +11d = -48
jika beda = -8
2a -88 = -48
2a = 40
a =20
maka suku ke 9
20 + 8 x-8 = 20 -64 = -44

Answer 2

B = -8
U5 + U8 = -48
(a+4b)+(a+7b)= -48
2a + 11b = -48
2a + 11(-8) = -48
2a - 88 = -48
2a = -48 +88
2a = 40
a = 20

Jadi
U9 = a +8b
U9 = 20 + 8(-8)
U9 = 20-64
U9 = -44 (D)
smga bermanfaat ^^